Clista Clanton MSLS AHIPJune 28 amp 29 2012

Todayrsquos topics

What is EBM Why is it important ComplementaryAlternative medicine Developing the ldquowell builtrdquo clinical

question Searching for evidence Evaluating the evidence

What is evidence based medicine (EBM)

ldquothe conscientious explicit and judicious use of current best evidence in making decisions about the care of individual patientsrdquo

The integration of individual clinical expertise with the best available external clinical evidence from systematic research

Initially proposed by Dr David Sackett and colleagues at McMasters University in Ontario Canada

Sackett DL et al Evidence-Based Medicine What it is and what it isnrsquot BMJ 1996 31271-2

Adapted from Sackett DL Rosenberg MC Gray JA Haynes RB Richardson WS (1996) Evidence based medicine what it is and what it isnt BMJ 312 71-72

Why is EBM important New types of evidence are being

generated which can create changes in the way patients are treated

Although evidence is needed on a daily basis usually physicians donrsquot get it

How much is actually being applied to patient care

1 lack of time

2 out-of-date textbooks and

3 the disorganization of the up-to-date journals6

Covell DG Uman GC Manning PR Information needs in office practice Are they being met Ann Intern Med 1985103596-9

Why is EBM important Up-to-date knowledge and clinical

performance can deteriorate with time There is a statistically and clinically significant negative

correlation between a physicianrsquos knowledge of up to date care and the years that have elapsed since graduation from medical school

Ramsey PG Carline JD Inui TS et al Changes over time in the knowledge base of practicing internists JAMA 19912661103-7Davis DA Thompson MA Oxman AD Haynes RB Changing physician performance A systematic review of the effect of continuing medical education strategies JAMA 1995274700-5

Traditional continuing medical education programs have not been shown to improve clinical performance Systematic reviews of the relevant randomized trials have

shown that traditional instructional CME fails to modify clinical performance and is ineffective in improving the health outcomes of patients

Why is EBM important Knowledge translation

ndash increasing the uptake of the best available evidence into practice ndash has always been a challenge Scurvy use of citrus

was proven to prevent and cure scurvy in 1754 but it was almost 50 years after the data was published before lemon juice was added to British ships

Additive to diet (n=2 in each group

Observed effect

Quart of cider Minor improvement

Unspecified elixir tds No change

Seawater No change

Garlic mustard and horseradish

No change

Spoonfuls of vinegar No change

Two oranges and a lemon

Dramatic recovery

Table 1 Lindrsquos study on scurvy1747

The James Lind Library Available from httpwwwjameslindlibraryorg Accessed 26 June 2008

Todayrsquos topics

What is EBM Why is it important ComplementaryAlternative medicine Developing the ldquowell builtrdquo clinical

question Searching for evidence Evaluating the evidence

What is evidence based medicine (EBM)

ldquothe conscientious explicit and judicious use of current best evidence in making decisions about the care of individual patientsrdquo

The integration of individual clinical expertise with the best available external clinical evidence from systematic research

Initially proposed by Dr David Sackett and colleagues at McMasters University in Ontario Canada

Sackett DL et al Evidence-Based Medicine What it is and what it isnrsquot BMJ 1996 31271-2

Adapted from Sackett DL Rosenberg MC Gray JA Haynes RB Richardson WS (1996) Evidence based medicine what it is and what it isnt BMJ 312 71-72

Why is EBM important New types of evidence are being

generated which can create changes in the way patients are treated

Although evidence is needed on a daily basis usually physicians donrsquot get it

How much is actually being applied to patient care

1 lack of time

2 out-of-date textbooks and

3 the disorganization of the up-to-date journals6

Covell DG Uman GC Manning PR Information needs in office practice Are they being met Ann Intern Med 1985103596-9

Why is EBM important Up-to-date knowledge and clinical

performance can deteriorate with time There is a statistically and clinically significant negative

correlation between a physicianrsquos knowledge of up to date care and the years that have elapsed since graduation from medical school

Ramsey PG Carline JD Inui TS et al Changes over time in the knowledge base of practicing internists JAMA 19912661103-7Davis DA Thompson MA Oxman AD Haynes RB Changing physician performance A systematic review of the effect of continuing medical education strategies JAMA 1995274700-5

Traditional continuing medical education programs have not been shown to improve clinical performance Systematic reviews of the relevant randomized trials have

shown that traditional instructional CME fails to modify clinical performance and is ineffective in improving the health outcomes of patients

Why is EBM important Knowledge translation

ndash increasing the uptake of the best available evidence into practice ndash has always been a challenge Scurvy use of citrus

was proven to prevent and cure scurvy in 1754 but it was almost 50 years after the data was published before lemon juice was added to British ships

Additive to diet (n=2 in each group

Observed effect

Quart of cider Minor improvement

Unspecified elixir tds No change

Seawater No change

Garlic mustard and horseradish

No change

Spoonfuls of vinegar No change

Two oranges and a lemon

Dramatic recovery

Table 1 Lindrsquos study on scurvy1747

The James Lind Library Available from httpwwwjameslindlibraryorg Accessed 26 June 2008

What is evidence based medicine (EBM)

ldquothe conscientious explicit and judicious use of current best evidence in making decisions about the care of individual patientsrdquo

The integration of individual clinical expertise with the best available external clinical evidence from systematic research

Initially proposed by Dr David Sackett and colleagues at McMasters University in Ontario Canada

Sackett DL et al Evidence-Based Medicine What it is and what it isnrsquot BMJ 1996 31271-2

Adapted from Sackett DL Rosenberg MC Gray JA Haynes RB Richardson WS (1996) Evidence based medicine what it is and what it isnt BMJ 312 71-72

Why is EBM important New types of evidence are being

generated which can create changes in the way patients are treated

Although evidence is needed on a daily basis usually physicians donrsquot get it

How much is actually being applied to patient care

1 lack of time

2 out-of-date textbooks and

3 the disorganization of the up-to-date journals6

Covell DG Uman GC Manning PR Information needs in office practice Are they being met Ann Intern Med 1985103596-9

Why is EBM important Up-to-date knowledge and clinical

performance can deteriorate with time There is a statistically and clinically significant negative

correlation between a physicianrsquos knowledge of up to date care and the years that have elapsed since graduation from medical school

Ramsey PG Carline JD Inui TS et al Changes over time in the knowledge base of practicing internists JAMA 19912661103-7Davis DA Thompson MA Oxman AD Haynes RB Changing physician performance A systematic review of the effect of continuing medical education strategies JAMA 1995274700-5

Traditional continuing medical education programs have not been shown to improve clinical performance Systematic reviews of the relevant randomized trials have

shown that traditional instructional CME fails to modify clinical performance and is ineffective in improving the health outcomes of patients

Why is EBM important Knowledge translation

ndash increasing the uptake of the best available evidence into practice ndash has always been a challenge Scurvy use of citrus

was proven to prevent and cure scurvy in 1754 but it was almost 50 years after the data was published before lemon juice was added to British ships

Additive to diet (n=2 in each group

Observed effect

Quart of cider Minor improvement

Unspecified elixir tds No change

Seawater No change

Garlic mustard and horseradish

No change

Spoonfuls of vinegar No change

Two oranges and a lemon

Dramatic recovery

Table 1 Lindrsquos study on scurvy1747

The James Lind Library Available from httpwwwjameslindlibraryorg Accessed 26 June 2008

Adapted from Sackett DL Rosenberg MC Gray JA Haynes RB Richardson WS (1996) Evidence based medicine what it is and what it isnt BMJ 312 71-72

Why is EBM important New types of evidence are being

generated which can create changes in the way patients are treated

Although evidence is needed on a daily basis usually physicians donrsquot get it

How much is actually being applied to patient care

1 lack of time

2 out-of-date textbooks and

3 the disorganization of the up-to-date journals6

Covell DG Uman GC Manning PR Information needs in office practice Are they being met Ann Intern Med 1985103596-9

Why is EBM important Up-to-date knowledge and clinical

performance can deteriorate with time There is a statistically and clinically significant negative

correlation between a physicianrsquos knowledge of up to date care and the years that have elapsed since graduation from medical school

Ramsey PG Carline JD Inui TS et al Changes over time in the knowledge base of practicing internists JAMA 19912661103-7Davis DA Thompson MA Oxman AD Haynes RB Changing physician performance A systematic review of the effect of continuing medical education strategies JAMA 1995274700-5

Traditional continuing medical education programs have not been shown to improve clinical performance Systematic reviews of the relevant randomized trials have

shown that traditional instructional CME fails to modify clinical performance and is ineffective in improving the health outcomes of patients

Why is EBM important Knowledge translation

ndash increasing the uptake of the best available evidence into practice ndash has always been a challenge Scurvy use of citrus

was proven to prevent and cure scurvy in 1754 but it was almost 50 years after the data was published before lemon juice was added to British ships

Additive to diet (n=2 in each group

Observed effect

Quart of cider Minor improvement

Unspecified elixir tds No change

Seawater No change

Garlic mustard and horseradish

No change

Spoonfuls of vinegar No change

Two oranges and a lemon

Dramatic recovery

Table 1 Lindrsquos study on scurvy1747

The James Lind Library Available from httpwwwjameslindlibraryorg Accessed 26 June 2008

Why is EBM important New types of evidence are being

generated which can create changes in the way patients are treated

Although evidence is needed on a daily basis usually physicians donrsquot get it

How much is actually being applied to patient care

1 lack of time

2 out-of-date textbooks and

3 the disorganization of the up-to-date journals6

Covell DG Uman GC Manning PR Information needs in office practice Are they being met Ann Intern Med 1985103596-9

Why is EBM important Up-to-date knowledge and clinical

performance can deteriorate with time There is a statistically and clinically significant negative

correlation between a physicianrsquos knowledge of up to date care and the years that have elapsed since graduation from medical school

Ramsey PG Carline JD Inui TS et al Changes over time in the knowledge base of practicing internists JAMA 19912661103-7Davis DA Thompson MA Oxman AD Haynes RB Changing physician performance A systematic review of the effect of continuing medical education strategies JAMA 1995274700-5

Traditional continuing medical education programs have not been shown to improve clinical performance Systematic reviews of the relevant randomized trials have

shown that traditional instructional CME fails to modify clinical performance and is ineffective in improving the health outcomes of patients

Why is EBM important Knowledge translation

ndash increasing the uptake of the best available evidence into practice ndash has always been a challenge Scurvy use of citrus

was proven to prevent and cure scurvy in 1754 but it was almost 50 years after the data was published before lemon juice was added to British ships

Additive to diet (n=2 in each group

Observed effect

Quart of cider Minor improvement

Unspecified elixir tds No change

Seawater No change

Garlic mustard and horseradish

No change

Spoonfuls of vinegar No change

Two oranges and a lemon

Dramatic recovery

Table 1 Lindrsquos study on scurvy1747

The James Lind Library Available from httpwwwjameslindlibraryorg Accessed 26 June 2008

Why is EBM important Up-to-date knowledge and clinical

performance can deteriorate with time There is a statistically and clinically significant negative

correlation between a physicianrsquos knowledge of up to date care and the years that have elapsed since graduation from medical school

Ramsey PG Carline JD Inui TS et al Changes over time in the knowledge base of practicing internists JAMA 19912661103-7Davis DA Thompson MA Oxman AD Haynes RB Changing physician performance A systematic review of the effect of continuing medical education strategies JAMA 1995274700-5

Traditional continuing medical education programs have not been shown to improve clinical performance Systematic reviews of the relevant randomized trials have

shown that traditional instructional CME fails to modify clinical performance and is ineffective in improving the health outcomes of patients

Why is EBM important Knowledge translation

ndash increasing the uptake of the best available evidence into practice ndash has always been a challenge Scurvy use of citrus

was proven to prevent and cure scurvy in 1754 but it was almost 50 years after the data was published before lemon juice was added to British ships

Additive to diet (n=2 in each group

Observed effect

Quart of cider Minor improvement

Unspecified elixir tds No change

Seawater No change

Garlic mustard and horseradish

No change

Spoonfuls of vinegar No change

Two oranges and a lemon

Dramatic recovery

Table 1 Lindrsquos study on scurvy1747

The James Lind Library Available from httpwwwjameslindlibraryorg Accessed 26 June 2008

Why is EBM important Knowledge translation

ndash increasing the uptake of the best available evidence into practice ndash has always been a challenge Scurvy use of citrus

was proven to prevent and cure scurvy in 1754 but it was almost 50 years after the data was published before lemon juice was added to British ships

Additive to diet (n=2 in each group

Observed effect

Quart of cider Minor improvement

Unspecified elixir tds No change

Seawater No change

Garlic mustard and horseradish

No change

Spoonfuls of vinegar No change

Two oranges and a lemon

Dramatic recovery

Table 1 Lindrsquos study on scurvy1747

The James Lind Library Available from httpwwwjameslindlibraryorg Accessed 26 June 2008

Puerperal fever mortality rates for the First and Second Clinic at the Vienna General Hospital 1841-1846 The top line is the First Clinic bottom line Second Clinic

Why is EBM important

Period

Characteristics of period No deliveries

No maternal deaths

Maternal deaths1000 deliveries

1784-1822

No routine post-mortems 71395 897 125

1823-1838

Routine post-mortems 65035 3745 576

1839-1847

Clinic arrangements changedFirst clinic doctors and studentsSecond clinic midwives

2020417791

1989 691

902338

1848-1859

Hand-washing introducedFirst clinicSecond clinic

4793840770

17121248

357306

Chloride of lime In 1846 Ignatz Semmelweis attributed puerperal fever to an infection carried by obstetricians Despite reducing maternal mortality from 18 to 12 by hand-washing in chloride of lime his findings were rejected by the medical society of Vienna It would take until the 1890rsquos before it was accepted that microorganisms can cause disease

Table 2 Mortality rates and characteristic of obstetrics clinics in Vienna 1784-1859

EBM processes can help with dissemination and adoption

ComplementaryAlternative Medicine Complementary and alternative medicine is a group

of diverse medical and health care systems practices and products that are not presently considered to be part of conventional medicine

National Center for Complementary and Alternative Medicine Understanding complementary and alternative medicine Available athttpnccamnihgovhealth

While some scientific evidence exists regarding some CAM therapies for most there are key questions that are yet to be answered through well-designed scientific studies--such as Are these therapies safe

Do these therapies work for the diseases or medical conditions for which they are used

Why is EBM important

Period

Characteristics of period No deliveries

No maternal deaths

Maternal deaths1000 deliveries

1784-1822

No routine post-mortems 71395 897 125

1823-1838

Routine post-mortems 65035 3745 576

1839-1847

Clinic arrangements changedFirst clinic doctors and studentsSecond clinic midwives

2020417791

1989 691

902338

1848-1859

Hand-washing introducedFirst clinicSecond clinic

4793840770

17121248

357306

Chloride of lime In 1846 Ignatz Semmelweis attributed puerperal fever to an infection carried by obstetricians Despite reducing maternal mortality from 18 to 12 by hand-washing in chloride of lime his findings were rejected by the medical society of Vienna It would take until the 1890rsquos before it was accepted that microorganisms can cause disease

Table 2 Mortality rates and characteristic of obstetrics clinics in Vienna 1784-1859

EBM processes can help with dissemination and adoption

ComplementaryAlternative Medicine Complementary and alternative medicine is a group

of diverse medical and health care systems practices and products that are not presently considered to be part of conventional medicine

National Center for Complementary and Alternative Medicine Understanding complementary and alternative medicine Available athttpnccamnihgovhealth

While some scientific evidence exists regarding some CAM therapies for most there are key questions that are yet to be answered through well-designed scientific studies--such as Are these therapies safe

Do these therapies work for the diseases or medical conditions for which they are used

EBM processes can help with dissemination and adoption

ComplementaryAlternative Medicine Complementary and alternative medicine is a group

of diverse medical and health care systems practices and products that are not presently considered to be part of conventional medicine

National Center for Complementary and Alternative Medicine Understanding complementary and alternative medicine Available athttpnccamnihgovhealth

While some scientific evidence exists regarding some CAM therapies for most there are key questions that are yet to be answered through well-designed scientific studies--such as Are these therapies safe

Do these therapies work for the diseases or medical conditions for which they are used

ComplementaryAlternative Medicine Complementary and alternative medicine is a group

of diverse medical and health care systems practices and products that are not presently considered to be part of conventional medicine

National Center for Complementary and Alternative Medicine Understanding complementary and alternative medicine Available athttpnccamnihgovhealth

While some scientific evidence exists regarding some CAM therapies for most there are key questions that are yet to be answered through well-designed scientific studies--such as Are these therapies safe

Do these therapies work for the diseases or medical conditions for which they are used

Are Complimentary and Alternative Medicine Interchangeable Terms

Complementary medicine is used together with conventional medicine Example Using aromatherapy to help lessen a patients discomfort following surgery

National Center for Complementary and Alternative Medicine Understanding complementary and alternative medicine Available at httpnccamnihgovhealth

Alternative medicine is used in place of conventional medicine Example When Suzanne Somers rejected chemotherapy in favor of a drug called Iscador (uses extracts of Mistletoe) to treat her breast cancer

Family Woman Died After Choosing Herbal Medicine Over Cancer Surgery

Studies estimate that 60 percent of cancer patients try unconventional remedies and about 40 percent take vitamin or dietary supplements

None has turned out to be a cure although some show promise for easing symptoms Touch therapies mind-body approaches and acupuncture may reduce stress and relieve pain nausea dry mouth and possibly hot flashes and are recommended by many top cancer experts A recent study found that ginger capsules eased nausea if started days before chemotherapy

One quarter of supplements tested by an independent company over the last decade have had some sort of problem Some contained contaminants Others had contents that did not match label claims Some had ingredients that exceeded safe limits Some contained real drugs masquerading as natural supplements

$25 billion spent no alternative cures found Big government-funded studies show most work no better than placebosThe Associated Pressupdated 1115 am CT Wed June 10 2009BETHESDA Md - Ten years ago the government set out to test herbal and other alternative health remedies to find the ones that work After spending $25 billion the disappointing answer seems to be that almost none of them doEchinacea for colds Ginkgo biloba for memory Glucosamine and chondroitin for arthritis Black cohosh for menopausal hot flashes Saw palmetto for prostate problems Shark cartilage for cancer All proved no better than dummy pills in big studies funded by the National Center for Complementary and Alternative Medicine The lone exception ginger capsules may help chemotherapy nauseaAs for therapies acupuncture has been shown to help certain conditions and yoga massage meditation and other relaxation methods may relieve symptoms like pain anxiety and fatigue

Major Types of Complementary and Alternative Medicine

Alternative medicine systems Built upon complete systems of theory and practice Examples homeopathic medicine naturopathic medicine traditional Chinese medicine Ayurveda

National Center for Complementary and Alternative Medicine Understanding complementary and alternative medicine Available at httpnccamnihgovhealth

Mind-body interventions Uses a variety of techniques designed to enhance the minds capacity to affect bodily function and symptoms Some techniques that were considered CAM in the past have become mainstream (patient support groups and cognitive-behavioral therapy) Other mind-body techniques are still considered CAM including meditation prayer mental healing and therapies that use creative outlets such as art music or dance

$25 billion spent no alternative cures found Big government-funded studies show most work no better than placebosThe Associated Pressupdated 1115 am CT Wed June 10 2009BETHESDA Md - Ten years ago the government set out to test herbal and other alternative health remedies to find the ones that work After spending $25 billion the disappointing answer seems to be that almost none of them doEchinacea for colds Ginkgo biloba for memory Glucosamine and chondroitin for arthritis Black cohosh for menopausal hot flashes Saw palmetto for prostate problems Shark cartilage for cancer All proved no better than dummy pills in big studies funded by the National Center for Complementary and Alternative Medicine The lone exception ginger capsules may help chemotherapy nauseaAs for therapies acupuncture has been shown to help certain conditions and yoga massage meditation and other relaxation methods may relieve symptoms like pain anxiety and fatigue

Major Types of Complementary and Alternative Medicine

Alternative medicine systems Built upon complete systems of theory and practice Examples homeopathic medicine naturopathic medicine traditional Chinese medicine Ayurveda

National Center for Complementary and Alternative Medicine Understanding complementary and alternative medicine Available at httpnccamnihgovhealth

Mind-body interventions Uses a variety of techniques designed to enhance the minds capacity to affect bodily function and symptoms Some techniques that were considered CAM in the past have become mainstream (patient support groups and cognitive-behavioral therapy) Other mind-body techniques are still considered CAM including meditation prayer mental healing and therapies that use creative outlets such as art music or dance

Major Types of Complementary and Alternative Medicine

Alternative medicine systems Built upon complete systems of theory and practice Examples homeopathic medicine naturopathic medicine traditional Chinese medicine Ayurveda

National Center for Complementary and Alternative Medicine Understanding complementary and alternative medicine Available at httpnccamnihgovhealth

Mind-body interventions Uses a variety of techniques designed to enhance the minds capacity to affect bodily function and symptoms Some techniques that were considered CAM in the past have become mainstream (patient support groups and cognitive-behavioral therapy) Other mind-body techniques are still considered CAM including meditation prayer mental healing and therapies that use creative outlets such as art music or dance

Major Types of Complementary and Alternative Medicine cont

Biologically Based Therapies Use substances found in nature (herbs foods and vitamins) Example shark cartilage to treat cancer

National Center for Complementary and Alternative Medicine Understanding complementary and alternative medicine Available at httpnccamnihgovhealth

Examples of dietary supplements that have been incorporated into mainstream medicine

Folic acid to prevent birth defects

Regimen of vitamins and zinc to slow the progression age-related macular degeneration (AMD)

Major Types of Complementary and Alternative Medicine cont

Manipulative or Body-Based Methods Based on manipulation andor movement of one or more parts of the body Examples chiropractic or osteopathic manipulation massage

National Center for Complementary and Alternative Medicine Understanding complementary and alternative medicine Available at httpnccamnihgovhealth

Energy Therapies Involve the use of energy fields Biofield therapies intended to affect energy fields that

purportedly surround and penetrate the human body (the existence of such fields has not yet been scientifically proven) Examples qi gong Reiki Therapeutic Touch

Bioelectromagnetic-based therapies unconventional use of electromagnetic fields such as pulsed fields magnetic fields or alternating-current or direct-current fields

NCCAM

National Center for Complementary and Alternative Medicine Part of NIH established in 1998 Dedicated to exploring complementary and

alternative healing practices in the context of rigorous science training complementary and alternative medicine (CAM) researchers and disseminating authoritative information to the public and professionals

NCCAM Web site (nccamnihgov) publications information for researchers frequently asked questions and links to other CAM-related resources

What is EBM ldquoEvidenced-based medicine is the concept of

formalizing the

scientific approach to the practice of medicine for identification

of ldquoevidencerdquo to support our clinical decisions It requires an

understanding of critical appraisal and the basic epidemiologic

principles of study design point estimates relative risk odds

ratios confidence intervals bias and confounding By using this

information clinicians can categorize evidence assess causality

and make evidence-based recommendations Evidence-based

medicine allows analysis of complicated material so that we can

make the best possible clinical decisions for the populations we

serverdquo

Williams JK Understanding evidence-based medicine a primer Am J Obstet Gynecol 2001185-275-278

Developing the clinical question

Step 1 Formulate the clinical issue into a searchable answerable question

Step 2 Distinguish what type of question you may have

Background

Foreground

Experience with Condition

Background questions

Background questions ask for general information about a condition or thing A question root (who what when etc)

combined with a verb

Background questions are typically answered by textbooks

What microbial organisms can cause community-acquired pneumonia

Foreground questions

Foreground questions ask for specific knowledge about a specific patient with a specific condition

Foreground questions are typically answered by databases that access the

research literature

Is St Johnrsquos Wort effective in relieving the symptoms of post-partum depression

Developing the question

Foreground questions usually have four components

P = Patient population

I = Intervention

C = Comparison

O = Outcome

Patient populationdisease

The patient population or disease of interest- age- gender- ethnicity- with certain disorder (eg hepatitis)

Intervention The intervention or range of interventions of interest- Exposure to disease- Prognostic factor A- Risk behavior (eg smoking)

Comparison What you want to compare the intervention against- No disease- Placebo or no interventiontherapy- Prognostic factor B- Absence of risk factor (eg non-smoking)

Outcome Outcome of interest- Risk of disease- Accuracy of diagnosis- Rate of occurrence of adverse outcome (eg death)

PICO Components of an answerable searchable question

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

In patients with chronic pain does the use of progressive muscle relaxation lead to a lessening of pain In patients with significant anterior or posterior vaginal wall prolapse do vaginal cones help In patients with moderate depression is St Johnrsquos Wort vs traditional SSRIrsquos effective in relieving symptoms with fewer adverse effects

Types of Questions

Diagnosis How to select a diagnostic test or how to interpret the results of a particular test

Prognosis What is the patients likely course of disease or how to screen for or reduce risk

Therapy Which treatment is the most effective or what is an effective treatment for a particular condition

Harm or Etiology Are there harmful effects of a particular treatment or how these harmful effects can be avoided

Prevention How can the patients risk factors be adjusted to help reduce the risk of disease

Cost Looks at cost effectiveness costbenefit analysis

Question Templates for Asking PICO Questions

TherapyIn __________________ what is the effect of ____________________ on ______________________ compared with __________________

EtiologyAre ______________ who have _________________ at ________________ risk forof ____________________ compared with _____________________ withwithout ______________________

Diagnosis or Diagnostic TestAre (Is) _________________________ more accurate in diagnosing ________________ compared with ________________

PreventionFor _________________ does the use of _______________ reduce the future risk of ________________ compared with _________________

PrognosisDoes _______________ influence _________________ in patients who have __________________

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

Medical literature

Primary ndash original research Experimental (an

intervention is made or variables are manipulated) Randomized Control

Trials Controlled trials

Observational (no intervention or variables are manipulated) Cohort studies Case-control studies Case reports

Secondary ndash reviews of original research Meta-analysis Systematic reviews Practice guidelines Reviews Decision analysis Consensus reports Editorial commentary

Case seriescase reports

Reports on treatment etc of individual patients

Anbar RD Savedoff AD Treatment of binge eating with automatic word processing and self-hypnosis a case reportAm J Clin Hypn 2005 Oct-2006 Jan48(2-3)191-8

Binge eating frequently is related to emotional stress and mood problems In this report we describe a 16-year-old boy who utilized automatic word processing (AWP) and self-hypnosis techniques in treatment of his binge eating and associated anxiety insomnia migraine headaches nausea and stomachaches He was able to reduce his anxiety by gaining an understanding that it originated as a result of fear of failure He developed a new cognitive strategy through AWP after which his binge eating resolved and his other symptoms improved with the aid of self-hypnosis Thus AWP may have helped achieve resolution of his binge eating by uncovering the underlying psychological causes of his symptoms and self-hypnosis may have given him a tool to implement a desired change in his behavior

Developing the clinical question

Step 1 Formulate the clinical issue into a searchable answerable question

Step 2 Distinguish what type of question you may have

Background

Foreground

Experience with Condition

Background questions

Background questions ask for general information about a condition or thing A question root (who what when etc)

combined with a verb

Background questions are typically answered by textbooks

What microbial organisms can cause community-acquired pneumonia

Foreground questions

Foreground questions ask for specific knowledge about a specific patient with a specific condition

Foreground questions are typically answered by databases that access the

research literature

Is St Johnrsquos Wort effective in relieving the symptoms of post-partum depression

Developing the question

Foreground questions usually have four components

P = Patient population

I = Intervention

C = Comparison

O = Outcome

Patient populationdisease

The patient population or disease of interest- age- gender- ethnicity- with certain disorder (eg hepatitis)

Intervention The intervention or range of interventions of interest- Exposure to disease- Prognostic factor A- Risk behavior (eg smoking)

Comparison What you want to compare the intervention against- No disease- Placebo or no interventiontherapy- Prognostic factor B- Absence of risk factor (eg non-smoking)

Outcome Outcome of interest- Risk of disease- Accuracy of diagnosis- Rate of occurrence of adverse outcome (eg death)

PICO Components of an answerable searchable question

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

In patients with chronic pain does the use of progressive muscle relaxation lead to a lessening of pain In patients with significant anterior or posterior vaginal wall prolapse do vaginal cones help In patients with moderate depression is St Johnrsquos Wort vs traditional SSRIrsquos effective in relieving symptoms with fewer adverse effects

Types of Questions

Diagnosis How to select a diagnostic test or how to interpret the results of a particular test

Prognosis What is the patients likely course of disease or how to screen for or reduce risk

Therapy Which treatment is the most effective or what is an effective treatment for a particular condition

Harm or Etiology Are there harmful effects of a particular treatment or how these harmful effects can be avoided

Prevention How can the patients risk factors be adjusted to help reduce the risk of disease

Cost Looks at cost effectiveness costbenefit analysis

Question Templates for Asking PICO Questions

TherapyIn __________________ what is the effect of ____________________ on ______________________ compared with __________________

EtiologyAre ______________ who have _________________ at ________________ risk forof ____________________ compared with _____________________ withwithout ______________________

Diagnosis or Diagnostic TestAre (Is) _________________________ more accurate in diagnosing ________________ compared with ________________

PreventionFor _________________ does the use of _______________ reduce the future risk of ________________ compared with _________________

PrognosisDoes _______________ influence _________________ in patients who have __________________

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

Medical literature

Primary ndash original research Experimental (an

intervention is made or variables are manipulated) Randomized Control

Trials Controlled trials

Observational (no intervention or variables are manipulated) Cohort studies Case-control studies Case reports

Secondary ndash reviews of original research Meta-analysis Systematic reviews Practice guidelines Reviews Decision analysis Consensus reports Editorial commentary

Case seriescase reports

Reports on treatment etc of individual patients

Anbar RD Savedoff AD Treatment of binge eating with automatic word processing and self-hypnosis a case reportAm J Clin Hypn 2005 Oct-2006 Jan48(2-3)191-8

Binge eating frequently is related to emotional stress and mood problems In this report we describe a 16-year-old boy who utilized automatic word processing (AWP) and self-hypnosis techniques in treatment of his binge eating and associated anxiety insomnia migraine headaches nausea and stomachaches He was able to reduce his anxiety by gaining an understanding that it originated as a result of fear of failure He developed a new cognitive strategy through AWP after which his binge eating resolved and his other symptoms improved with the aid of self-hypnosis Thus AWP may have helped achieve resolution of his binge eating by uncovering the underlying psychological causes of his symptoms and self-hypnosis may have given him a tool to implement a desired change in his behavior

Background questions

Background questions ask for general information about a condition or thing A question root (who what when etc)

combined with a verb

Background questions are typically answered by textbooks

What microbial organisms can cause community-acquired pneumonia

Foreground questions

Foreground questions ask for specific knowledge about a specific patient with a specific condition

Foreground questions are typically answered by databases that access the

research literature

Is St Johnrsquos Wort effective in relieving the symptoms of post-partum depression

Developing the question

Foreground questions usually have four components

P = Patient population

I = Intervention

C = Comparison

O = Outcome

Patient populationdisease

The patient population or disease of interest- age- gender- ethnicity- with certain disorder (eg hepatitis)

Intervention The intervention or range of interventions of interest- Exposure to disease- Prognostic factor A- Risk behavior (eg smoking)

Comparison What you want to compare the intervention against- No disease- Placebo or no interventiontherapy- Prognostic factor B- Absence of risk factor (eg non-smoking)

Outcome Outcome of interest- Risk of disease- Accuracy of diagnosis- Rate of occurrence of adverse outcome (eg death)

PICO Components of an answerable searchable question

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

In patients with chronic pain does the use of progressive muscle relaxation lead to a lessening of pain In patients with significant anterior or posterior vaginal wall prolapse do vaginal cones help In patients with moderate depression is St Johnrsquos Wort vs traditional SSRIrsquos effective in relieving symptoms with fewer adverse effects

Types of Questions

Diagnosis How to select a diagnostic test or how to interpret the results of a particular test

Prognosis What is the patients likely course of disease or how to screen for or reduce risk

Therapy Which treatment is the most effective or what is an effective treatment for a particular condition

Harm or Etiology Are there harmful effects of a particular treatment or how these harmful effects can be avoided

Prevention How can the patients risk factors be adjusted to help reduce the risk of disease

Cost Looks at cost effectiveness costbenefit analysis

Question Templates for Asking PICO Questions

TherapyIn __________________ what is the effect of ____________________ on ______________________ compared with __________________

EtiologyAre ______________ who have _________________ at ________________ risk forof ____________________ compared with _____________________ withwithout ______________________

Diagnosis or Diagnostic TestAre (Is) _________________________ more accurate in diagnosing ________________ compared with ________________

PreventionFor _________________ does the use of _______________ reduce the future risk of ________________ compared with _________________

PrognosisDoes _______________ influence _________________ in patients who have __________________

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

Medical literature

Primary ndash original research Experimental (an

intervention is made or variables are manipulated) Randomized Control

Trials Controlled trials

Observational (no intervention or variables are manipulated) Cohort studies Case-control studies Case reports

Secondary ndash reviews of original research Meta-analysis Systematic reviews Practice guidelines Reviews Decision analysis Consensus reports Editorial commentary

Case seriescase reports

Reports on treatment etc of individual patients

Anbar RD Savedoff AD Treatment of binge eating with automatic word processing and self-hypnosis a case reportAm J Clin Hypn 2005 Oct-2006 Jan48(2-3)191-8

Binge eating frequently is related to emotional stress and mood problems In this report we describe a 16-year-old boy who utilized automatic word processing (AWP) and self-hypnosis techniques in treatment of his binge eating and associated anxiety insomnia migraine headaches nausea and stomachaches He was able to reduce his anxiety by gaining an understanding that it originated as a result of fear of failure He developed a new cognitive strategy through AWP after which his binge eating resolved and his other symptoms improved with the aid of self-hypnosis Thus AWP may have helped achieve resolution of his binge eating by uncovering the underlying psychological causes of his symptoms and self-hypnosis may have given him a tool to implement a desired change in his behavior

Foreground questions

Foreground questions ask for specific knowledge about a specific patient with a specific condition

Foreground questions are typically answered by databases that access the

research literature

Is St Johnrsquos Wort effective in relieving the symptoms of post-partum depression

Developing the question

Foreground questions usually have four components

P = Patient population

I = Intervention

C = Comparison

O = Outcome

Patient populationdisease

The patient population or disease of interest- age- gender- ethnicity- with certain disorder (eg hepatitis)

Intervention The intervention or range of interventions of interest- Exposure to disease- Prognostic factor A- Risk behavior (eg smoking)

Comparison What you want to compare the intervention against- No disease- Placebo or no interventiontherapy- Prognostic factor B- Absence of risk factor (eg non-smoking)

Outcome Outcome of interest- Risk of disease- Accuracy of diagnosis- Rate of occurrence of adverse outcome (eg death)

PICO Components of an answerable searchable question

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

In patients with chronic pain does the use of progressive muscle relaxation lead to a lessening of pain In patients with significant anterior or posterior vaginal wall prolapse do vaginal cones help In patients with moderate depression is St Johnrsquos Wort vs traditional SSRIrsquos effective in relieving symptoms with fewer adverse effects

Types of Questions

Diagnosis How to select a diagnostic test or how to interpret the results of a particular test

Prognosis What is the patients likely course of disease or how to screen for or reduce risk

Therapy Which treatment is the most effective or what is an effective treatment for a particular condition

Harm or Etiology Are there harmful effects of a particular treatment or how these harmful effects can be avoided

Prevention How can the patients risk factors be adjusted to help reduce the risk of disease

Cost Looks at cost effectiveness costbenefit analysis

Question Templates for Asking PICO Questions

TherapyIn __________________ what is the effect of ____________________ on ______________________ compared with __________________

EtiologyAre ______________ who have _________________ at ________________ risk forof ____________________ compared with _____________________ withwithout ______________________

Diagnosis or Diagnostic TestAre (Is) _________________________ more accurate in diagnosing ________________ compared with ________________

PreventionFor _________________ does the use of _______________ reduce the future risk of ________________ compared with _________________

PrognosisDoes _______________ influence _________________ in patients who have __________________

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

Medical literature

Primary ndash original research Experimental (an

intervention is made or variables are manipulated) Randomized Control

Trials Controlled trials

Observational (no intervention or variables are manipulated) Cohort studies Case-control studies Case reports

Secondary ndash reviews of original research Meta-analysis Systematic reviews Practice guidelines Reviews Decision analysis Consensus reports Editorial commentary

Case seriescase reports

Reports on treatment etc of individual patients

Anbar RD Savedoff AD Treatment of binge eating with automatic word processing and self-hypnosis a case reportAm J Clin Hypn 2005 Oct-2006 Jan48(2-3)191-8

Binge eating frequently is related to emotional stress and mood problems In this report we describe a 16-year-old boy who utilized automatic word processing (AWP) and self-hypnosis techniques in treatment of his binge eating and associated anxiety insomnia migraine headaches nausea and stomachaches He was able to reduce his anxiety by gaining an understanding that it originated as a result of fear of failure He developed a new cognitive strategy through AWP after which his binge eating resolved and his other symptoms improved with the aid of self-hypnosis Thus AWP may have helped achieve resolution of his binge eating by uncovering the underlying psychological causes of his symptoms and self-hypnosis may have given him a tool to implement a desired change in his behavior

Developing the question

Foreground questions usually have four components

P = Patient population

I = Intervention

C = Comparison

O = Outcome

Patient populationdisease

The patient population or disease of interest- age- gender- ethnicity- with certain disorder (eg hepatitis)

Intervention The intervention or range of interventions of interest- Exposure to disease- Prognostic factor A- Risk behavior (eg smoking)

Comparison What you want to compare the intervention against- No disease- Placebo or no interventiontherapy- Prognostic factor B- Absence of risk factor (eg non-smoking)

Outcome Outcome of interest- Risk of disease- Accuracy of diagnosis- Rate of occurrence of adverse outcome (eg death)

PICO Components of an answerable searchable question

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

In patients with chronic pain does the use of progressive muscle relaxation lead to a lessening of pain In patients with significant anterior or posterior vaginal wall prolapse do vaginal cones help In patients with moderate depression is St Johnrsquos Wort vs traditional SSRIrsquos effective in relieving symptoms with fewer adverse effects

Types of Questions

Diagnosis How to select a diagnostic test or how to interpret the results of a particular test

Prognosis What is the patients likely course of disease or how to screen for or reduce risk

Therapy Which treatment is the most effective or what is an effective treatment for a particular condition

Harm or Etiology Are there harmful effects of a particular treatment or how these harmful effects can be avoided

Prevention How can the patients risk factors be adjusted to help reduce the risk of disease

Cost Looks at cost effectiveness costbenefit analysis

Question Templates for Asking PICO Questions

TherapyIn __________________ what is the effect of ____________________ on ______________________ compared with __________________

EtiologyAre ______________ who have _________________ at ________________ risk forof ____________________ compared with _____________________ withwithout ______________________

Diagnosis or Diagnostic TestAre (Is) _________________________ more accurate in diagnosing ________________ compared with ________________

PreventionFor _________________ does the use of _______________ reduce the future risk of ________________ compared with _________________

PrognosisDoes _______________ influence _________________ in patients who have __________________

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

Medical literature

Primary ndash original research Experimental (an

intervention is made or variables are manipulated) Randomized Control

Trials Controlled trials

Observational (no intervention or variables are manipulated) Cohort studies Case-control studies Case reports

Secondary ndash reviews of original research Meta-analysis Systematic reviews Practice guidelines Reviews Decision analysis Consensus reports Editorial commentary

Case seriescase reports

Reports on treatment etc of individual patients

Anbar RD Savedoff AD Treatment of binge eating with automatic word processing and self-hypnosis a case reportAm J Clin Hypn 2005 Oct-2006 Jan48(2-3)191-8

Binge eating frequently is related to emotional stress and mood problems In this report we describe a 16-year-old boy who utilized automatic word processing (AWP) and self-hypnosis techniques in treatment of his binge eating and associated anxiety insomnia migraine headaches nausea and stomachaches He was able to reduce his anxiety by gaining an understanding that it originated as a result of fear of failure He developed a new cognitive strategy through AWP after which his binge eating resolved and his other symptoms improved with the aid of self-hypnosis Thus AWP may have helped achieve resolution of his binge eating by uncovering the underlying psychological causes of his symptoms and self-hypnosis may have given him a tool to implement a desired change in his behavior

Patient populationdisease

The patient population or disease of interest- age- gender- ethnicity- with certain disorder (eg hepatitis)

Intervention The intervention or range of interventions of interest- Exposure to disease- Prognostic factor A- Risk behavior (eg smoking)

Comparison What you want to compare the intervention against- No disease- Placebo or no interventiontherapy- Prognostic factor B- Absence of risk factor (eg non-smoking)

Outcome Outcome of interest- Risk of disease- Accuracy of diagnosis- Rate of occurrence of adverse outcome (eg death)

PICO Components of an answerable searchable question

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

In patients with chronic pain does the use of progressive muscle relaxation lead to a lessening of pain In patients with significant anterior or posterior vaginal wall prolapse do vaginal cones help In patients with moderate depression is St Johnrsquos Wort vs traditional SSRIrsquos effective in relieving symptoms with fewer adverse effects

Types of Questions

Diagnosis How to select a diagnostic test or how to interpret the results of a particular test

Prognosis What is the patients likely course of disease or how to screen for or reduce risk

Therapy Which treatment is the most effective or what is an effective treatment for a particular condition

Harm or Etiology Are there harmful effects of a particular treatment or how these harmful effects can be avoided

Prevention How can the patients risk factors be adjusted to help reduce the risk of disease

Cost Looks at cost effectiveness costbenefit analysis

Question Templates for Asking PICO Questions

TherapyIn __________________ what is the effect of ____________________ on ______________________ compared with __________________

EtiologyAre ______________ who have _________________ at ________________ risk forof ____________________ compared with _____________________ withwithout ______________________

Diagnosis or Diagnostic TestAre (Is) _________________________ more accurate in diagnosing ________________ compared with ________________

PreventionFor _________________ does the use of _______________ reduce the future risk of ________________ compared with _________________

PrognosisDoes _______________ influence _________________ in patients who have __________________

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

Medical literature

Primary ndash original research Experimental (an

intervention is made or variables are manipulated) Randomized Control

Trials Controlled trials

Observational (no intervention or variables are manipulated) Cohort studies Case-control studies Case reports

Secondary ndash reviews of original research Meta-analysis Systematic reviews Practice guidelines Reviews Decision analysis Consensus reports Editorial commentary

Case seriescase reports

Reports on treatment etc of individual patients

Anbar RD Savedoff AD Treatment of binge eating with automatic word processing and self-hypnosis a case reportAm J Clin Hypn 2005 Oct-2006 Jan48(2-3)191-8

Binge eating frequently is related to emotional stress and mood problems In this report we describe a 16-year-old boy who utilized automatic word processing (AWP) and self-hypnosis techniques in treatment of his binge eating and associated anxiety insomnia migraine headaches nausea and stomachaches He was able to reduce his anxiety by gaining an understanding that it originated as a result of fear of failure He developed a new cognitive strategy through AWP after which his binge eating resolved and his other symptoms improved with the aid of self-hypnosis Thus AWP may have helped achieve resolution of his binge eating by uncovering the underlying psychological causes of his symptoms and self-hypnosis may have given him a tool to implement a desired change in his behavior

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

In patients with chronic pain does the use of progressive muscle relaxation lead to a lessening of pain In patients with significant anterior or posterior vaginal wall prolapse do vaginal cones help In patients with moderate depression is St Johnrsquos Wort vs traditional SSRIrsquos effective in relieving symptoms with fewer adverse effects

Types of Questions

Diagnosis How to select a diagnostic test or how to interpret the results of a particular test

Prognosis What is the patients likely course of disease or how to screen for or reduce risk

Therapy Which treatment is the most effective or what is an effective treatment for a particular condition

Harm or Etiology Are there harmful effects of a particular treatment or how these harmful effects can be avoided

Prevention How can the patients risk factors be adjusted to help reduce the risk of disease

Cost Looks at cost effectiveness costbenefit analysis

Question Templates for Asking PICO Questions

TherapyIn __________________ what is the effect of ____________________ on ______________________ compared with __________________

EtiologyAre ______________ who have _________________ at ________________ risk forof ____________________ compared with _____________________ withwithout ______________________

Diagnosis or Diagnostic TestAre (Is) _________________________ more accurate in diagnosing ________________ compared with ________________

PreventionFor _________________ does the use of _______________ reduce the future risk of ________________ compared with _________________

PrognosisDoes _______________ influence _________________ in patients who have __________________

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

Medical literature

Primary ndash original research Experimental (an

intervention is made or variables are manipulated) Randomized Control

Trials Controlled trials

Observational (no intervention or variables are manipulated) Cohort studies Case-control studies Case reports

Secondary ndash reviews of original research Meta-analysis Systematic reviews Practice guidelines Reviews Decision analysis Consensus reports Editorial commentary

Case seriescase reports

Reports on treatment etc of individual patients

Anbar RD Savedoff AD Treatment of binge eating with automatic word processing and self-hypnosis a case reportAm J Clin Hypn 2005 Oct-2006 Jan48(2-3)191-8

Binge eating frequently is related to emotional stress and mood problems In this report we describe a 16-year-old boy who utilized automatic word processing (AWP) and self-hypnosis techniques in treatment of his binge eating and associated anxiety insomnia migraine headaches nausea and stomachaches He was able to reduce his anxiety by gaining an understanding that it originated as a result of fear of failure He developed a new cognitive strategy through AWP after which his binge eating resolved and his other symptoms improved with the aid of self-hypnosis Thus AWP may have helped achieve resolution of his binge eating by uncovering the underlying psychological causes of his symptoms and self-hypnosis may have given him a tool to implement a desired change in his behavior

Types of Questions

Diagnosis How to select a diagnostic test or how to interpret the results of a particular test

Prognosis What is the patients likely course of disease or how to screen for or reduce risk

Therapy Which treatment is the most effective or what is an effective treatment for a particular condition

Harm or Etiology Are there harmful effects of a particular treatment or how these harmful effects can be avoided

Prevention How can the patients risk factors be adjusted to help reduce the risk of disease

Cost Looks at cost effectiveness costbenefit analysis

Question Templates for Asking PICO Questions

TherapyIn __________________ what is the effect of ____________________ on ______________________ compared with __________________

EtiologyAre ______________ who have _________________ at ________________ risk forof ____________________ compared with _____________________ withwithout ______________________

Diagnosis or Diagnostic TestAre (Is) _________________________ more accurate in diagnosing ________________ compared with ________________

PreventionFor _________________ does the use of _______________ reduce the future risk of ________________ compared with _________________

PrognosisDoes _______________ influence _________________ in patients who have __________________

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

Medical literature

Primary ndash original research Experimental (an

intervention is made or variables are manipulated) Randomized Control

Trials Controlled trials

Observational (no intervention or variables are manipulated) Cohort studies Case-control studies Case reports

Secondary ndash reviews of original research Meta-analysis Systematic reviews Practice guidelines Reviews Decision analysis Consensus reports Editorial commentary

Case seriescase reports

Reports on treatment etc of individual patients

Anbar RD Savedoff AD Treatment of binge eating with automatic word processing and self-hypnosis a case reportAm J Clin Hypn 2005 Oct-2006 Jan48(2-3)191-8

Binge eating frequently is related to emotional stress and mood problems In this report we describe a 16-year-old boy who utilized automatic word processing (AWP) and self-hypnosis techniques in treatment of his binge eating and associated anxiety insomnia migraine headaches nausea and stomachaches He was able to reduce his anxiety by gaining an understanding that it originated as a result of fear of failure He developed a new cognitive strategy through AWP after which his binge eating resolved and his other symptoms improved with the aid of self-hypnosis Thus AWP may have helped achieve resolution of his binge eating by uncovering the underlying psychological causes of his symptoms and self-hypnosis may have given him a tool to implement a desired change in his behavior

Question Templates for Asking PICO Questions

TherapyIn __________________ what is the effect of ____________________ on ______________________ compared with __________________

EtiologyAre ______________ who have _________________ at ________________ risk forof ____________________ compared with _____________________ withwithout ______________________

Diagnosis or Diagnostic TestAre (Is) _________________________ more accurate in diagnosing ________________ compared with ________________

PreventionFor _________________ does the use of _______________ reduce the future risk of ________________ compared with _________________

PrognosisDoes _______________ influence _________________ in patients who have __________________

Melnyk B M amp Fineout-Overholt E (2005) Evidence-based practice in nursing amp healthcare A guide to best practice Philadelphia PA Lippincott Williams amp Wilkins

Medical literature

Primary ndash original research Experimental (an

intervention is made or variables are manipulated) Randomized Control

Trials Controlled trials

Observational (no intervention or variables are manipulated) Cohort studies Case-control studies Case reports

Secondary ndash reviews of original research Meta-analysis Systematic reviews Practice guidelines Reviews Decision analysis Consensus reports Editorial commentary

Case seriescase reports

Reports on treatment etc of individual patients

Anbar RD Savedoff AD Treatment of binge eating with automatic word processing and self-hypnosis a case reportAm J Clin Hypn 2005 Oct-2006 Jan48(2-3)191-8

Binge eating frequently is related to emotional stress and mood problems In this report we describe a 16-year-old boy who utilized automatic word processing (AWP) and self-hypnosis techniques in treatment of his binge eating and associated anxiety insomnia migraine headaches nausea and stomachaches He was able to reduce his anxiety by gaining an understanding that it originated as a result of fear of failure He developed a new cognitive strategy through AWP after which his binge eating resolved and his other symptoms improved with the aid of self-hypnosis Thus AWP may have helped achieve resolution of his binge eating by uncovering the underlying psychological causes of his symptoms and self-hypnosis may have given him a tool to implement a desired change in his behavior

Medical literature

Primary ndash original research Experimental (an

intervention is made or variables are manipulated) Randomized Control

Trials Controlled trials

Observational (no intervention or variables are manipulated) Cohort studies Case-control studies Case reports

Secondary ndash reviews of original research Meta-analysis Systematic reviews Practice guidelines Reviews Decision analysis Consensus reports Editorial commentary

Case seriescase reports

Reports on treatment etc of individual patients

Anbar RD Savedoff AD Treatment of binge eating with automatic word processing and self-hypnosis a case reportAm J Clin Hypn 2005 Oct-2006 Jan48(2-3)191-8

Binge eating frequently is related to emotional stress and mood problems In this report we describe a 16-year-old boy who utilized automatic word processing (AWP) and self-hypnosis techniques in treatment of his binge eating and associated anxiety insomnia migraine headaches nausea and stomachaches He was able to reduce his anxiety by gaining an understanding that it originated as a result of fear of failure He developed a new cognitive strategy through AWP after which his binge eating resolved and his other symptoms improved with the aid of self-hypnosis Thus AWP may have helped achieve resolution of his binge eating by uncovering the underlying psychological causes of his symptoms and self-hypnosis may have given him a tool to implement a desired change in his behavior

Case seriescase reports

Reports on treatment etc of individual patients

Anbar RD Savedoff AD Treatment of binge eating with automatic word processing and self-hypnosis a case reportAm J Clin Hypn 2005 Oct-2006 Jan48(2-3)191-8

Binge eating frequently is related to emotional stress and mood problems In this report we describe a 16-year-old boy who utilized automatic word processing (AWP) and self-hypnosis techniques in treatment of his binge eating and associated anxiety insomnia migraine headaches nausea and stomachaches He was able to reduce his anxiety by gaining an understanding that it originated as a result of fear of failure He developed a new cognitive strategy through AWP after which his binge eating resolved and his other symptoms improved with the aid of self-hypnosis Thus AWP may have helped achieve resolution of his binge eating by uncovering the underlying psychological causes of his symptoms and self-hypnosis may have given him a tool to implement a desired change in his behavior

Case Control Studies

Studies in which patients who already have a specific condition are compared with people who do not

Rely on medical records and patient recall for data collection

Hepatitis C a retrospective study literature review and naturopathic protocol Milliman WB Lamson DW Brignall MS Alternative Medicine Review 5(4)355-71 2000 Aug

The standard medical treatment of hepatitis C infection is only associated with sustained efficacy in a minority of patients Therefore the search for other treatments is of utmost importance Several natural products and their derivatives have demonstrated benefit in the treatment of hepatitis C and other chronic liver conditions Other herbal and nutritional supplements have mechanisms of action that make them likely to be of benefit This article presents comprehensive protocol including diet lifestyle and therapeutic interventions The authors performed a retrospective review of 41 consecutive hepatitis C patients Of the 14 patients with baseline and follow-up data who had not undergone interferon therapy seven had a greater than 25-percent reduction in serum alanine aminotransferase (ALT) levels after at least one month on the protocol For all patients reviewed the average reduction in ALT was 35 UL (p=0026) These data appear to suggest that a conservative approach using diet and lifestyle modification along with safe and indicated interventions can be effective in the treatment of hepatitis C Controlled trials with serial liver biopsy and viral load data are necessary to confirm these preliminary findings

Hepatitis C a retrospective study literature review and naturopathic protocol Milliman WB Lamson DW Brignall MS Alternative Medicine Review 5(4)355-71 2000 Aug

The standard medical treatment of hepatitis C infection is only associated with sustained efficacy in a minority of patients Therefore the search for other treatments is of utmost importance Several natural products and their derivatives have demonstrated benefit in the treatment of hepatitis C and other chronic liver conditions Other herbal and nutritional supplements have mechanisms of action that make them likely to be of benefit This article presents comprehensive protocol including diet lifestyle and therapeutic interventions The authors performed a retrospective review of 41 consecutive hepatitis C patients Of the 14 patients with baseline and follow-up data who had not undergone interferon therapy seven had a greater than 25-percent reduction in serum alanine aminotransferase (ALT) levels after at least one month on the protocol For all patients reviewed the average reduction in ALT was 35 UL (p=0026) These data appear to suggest that a conservative approach using diet and lifestyle modification along with safe and indicated interventions can be effective in the treatment of hepatitis C Controlled trials with serial liver biopsy and viral load data are necessary to confirm these preliminary findings

Cohort studies

From a large population follows patients who have a specific condition or receive a particular treatment over time and compared with another group that has not been affected by the condition or treatment studies

Kristal AR Littman AJ Benitez D White EYoga practice is associated with attenuated weight gain in healthy middle-aged men and women Altern Ther Health Med 2005 Jul-Aug11(4)28-33BACKGROUND Yoga is promoted or weight maintenance but there is little evidence of its efficacy OBJECTIVE To examine whether yoga practice is associated with lower mean 10-year weight gain after age 45 PARTICIPANTS Participants included 15550 adults aged 53 to 57 years recruited to the Vitamin and Lifestyle (VITAL) cohort study between 2000 and 2002 MEASUREMENTS Physical activity (including yoga) during the past 10 years diet height and weight at recruitment and at ages 30 and 45 All measures were based on self-reporting and past weight was retrospectively ascertained METHODS Multiple regression analyses were used to examined covariate-adjusted associations between yoga practice and weight change from age 45 to recruitment and polychotomous logistic regression was used to examine associations of yoga practice with the relative odds of weight maintenance (within 5) and weight loss (gt 5) compared to weight gain RESULTS Yoga practice for four or more years was associated with a 31-lb lower weight gain among normal weight (BMI lt 25) participants [95 lbs versus 126 Ibs] and an 185-lb lower weight gain among overweight participants [-50 lbs versus 135 Ibs] (both P for trend lt001) Among overweight individuals 4+ years of yoga practice was associated with a relative odds of 185 (95 confidence interval [CI] 063-542) for weight maintenance (within 5) and 388 (95 Cl 130-988) for weight loss (gt 5) compared to weight gain (P for trend 026 and 003 respectively) CONCLUSIONS Regular yoga practice was associated with attenuated weight gain most strongly among individuals who were overweight Although causal inference from this observational study is not possible results are consistent with the hypothesis that regular yoga practice can benefit individuals who wish to maintain or lose weight

Kristal AR Littman AJ Benitez D White EYoga practice is associated with attenuated weight gain in healthy middle-aged men and women Altern Ther Health Med 2005 Jul-Aug11(4)28-33BACKGROUND Yoga is promoted or weight maintenance but there is little evidence of its efficacy OBJECTIVE To examine whether yoga practice is associated with lower mean 10-year weight gain after age 45 PARTICIPANTS Participants included 15550 adults aged 53 to 57 years recruited to the Vitamin and Lifestyle (VITAL) cohort study between 2000 and 2002 MEASUREMENTS Physical activity (including yoga) during the past 10 years diet height and weight at recruitment and at ages 30 and 45 All measures were based on self-reporting and past weight was retrospectively ascertained METHODS Multiple regression analyses were used to examined covariate-adjusted associations between yoga practice and weight change from age 45 to recruitment and polychotomous logistic regression was used to examine associations of yoga practice with the relative odds of weight maintenance (within 5) and weight loss (gt 5) compared to weight gain RESULTS Yoga practice for four or more years was associated with a 31-lb lower weight gain among normal weight (BMI lt 25) participants [95 lbs versus 126 Ibs] and an 185-lb lower weight gain among overweight participants [-50 lbs versus 135 Ibs] (both P for trend lt001) Among overweight individuals 4+ years of yoga practice was associated with a relative odds of 185 (95 confidence interval [CI] 063-542) for weight maintenance (within 5) and 388 (95 Cl 130-988) for weight loss (gt 5) compared to weight gain (P for trend 026 and 003 respectively) CONCLUSIONS Regular yoga practice was associated with attenuated weight gain most strongly among individuals who were overweight Although causal inference from this observational study is not possible results are consistent with the hypothesis that regular yoga practice can benefit individuals who wish to maintain or lose weight

Randomized controlled trials Study effect of therapy on real

patients Include methodologies that reduce

the potential for bias Intervention group vs control group Patients assigned in randomized

fashion Blinded or non-blinded studies

Harikumar R Raj M Paul A Harish K Kumar SK Sandesh K Asharaf S Thomas V Listening to music decreases need for sedative medication during colonoscopy a randomized controlled trial Indian J Gastroenterol 2006 Jan-Feb25(1)3-5

BACKGROUND Music played during endoscopic procedures may alleviate anxiety and improve patient acceptance of the procedure A prospective randomized controlled trial was undertaken to determine whether music decreases the requirement for midazolam during colonoscopy and makes the procedure more comfortable and acceptable METHODS Patients undergoing elective colonoscopy between October 2003 and February 2004 were randomized to either not listen to music (Group 1 n=40) or listen to music of their choice (Group 2 n=38) during the procedure All patients received intravenous midazolam on demand in aliquots of 2 mg each The dose of midazolam duration of procedure recovery time pain and discomfort scores and willingness to undergo a repeat procedure using the same sedation protocol were compared RESULTS Patients in Group 2 received significantly less midazolam than those in Group 1 (p=0007) The pain score was similar in the two groups whereas discomfort score was lower in Group 2 (p=0001) Patients in the two groups were equally likely to be willing for a repeat procedure CONCLUSION Listening to music during colonoscopy helps reduce the dose of sedative medications and decreases discomfort experienced during the procedure

Harikumar R Raj M Paul A Harish K Kumar SK Sandesh K Asharaf S Thomas V Listening to music decreases need for sedative medication during colonoscopy a randomized controlled trial Indian J Gastroenterol 2006 Jan-Feb25(1)3-5

BACKGROUND Music played during endoscopic procedures may alleviate anxiety and improve patient acceptance of the procedure A prospective randomized controlled trial was undertaken to determine whether music decreases the requirement for midazolam during colonoscopy and makes the procedure more comfortable and acceptable METHODS Patients undergoing elective colonoscopy between October 2003 and February 2004 were randomized to either not listen to music (Group 1 n=40) or listen to music of their choice (Group 2 n=38) during the procedure All patients received intravenous midazolam on demand in aliquots of 2 mg each The dose of midazolam duration of procedure recovery time pain and discomfort scores and willingness to undergo a repeat procedure using the same sedation protocol were compared RESULTS Patients in Group 2 received significantly less midazolam than those in Group 1 (p=0007) The pain score was similar in the two groups whereas discomfort score was lower in Group 2 (p=0001) Patients in the two groups were equally likely to be willing for a repeat procedure CONCLUSION Listening to music during colonoscopy helps reduce the dose of sedative medications and decreases discomfort experienced during the procedure

Systematic review

Extensive literature search is conducted in systematic fashion

Only uses studies with sound methodology

Studies are collected reviewed assessed and the results summarized according to predetermined criteria of the review question

Jepson RG Mihaljevic L Craig J Cranberries for preventing urinary tract infections The Cochrane Database of Systematic Reviews 2004 Issue 2 Background Cranberries (particularly in the form of cranberry juice) have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs) The aim of this review is to assess the effectiveness of cranberries in preventing such infectionsObjectives To assess the effectiveness of cranberry juice and other cranberry products in preventing UTIs in susceptible populationsSearch strategy Electronic databases and the Internet were searched using English and non English language terms companies involved with the promotion and distribution of cranberry preparations were contacted reference lists of review articles and relevant trials were searchedhellipsearched in February 2003Selection criteria All randomised or quasi randomised controlled trials of cranberry juiceproducts for the prevention of urinary tract infections in susceptible populations Trials of men women or children were includedData collection and analysis Two reviewers independently assessed and extracted information Information was collected on methods participants interventions and outcomes (urinary tract infections (symptomatic and asymptomatic) side effects and adherence to therapy) RR were calculated where appropriate otherwise a narrative synthesis was undertaken Quality was assessed using the Cochrane criteriaMain results Seven trials met the inclusion criteria (four cross-over three parallel group) The effectiveness of cranberry juice (or cranberry-lingonberry juice) versus placebo juice or water was evaluated in six trials and the effectiveness of cranberries tablets versus placebo was evaluated in two trials (one study evaluated both juice and tablets) In two good quality RCTs cranberry products significantly reduced the incidence of UTIs at twelve months (RR 061 95 CI040 to 091) compared with placebocontrol in women One trial gave 75 g cranberry concentrate daily (in 50 ml) the other gave 130 concentrate given either in 250 ml juice or in tablet form There was no significant difference in the incidence of UTIs between cranberry juice versus cranberry capsules (RR 111 95 CI049 to 250) Five trials were not included in the meta-analyses due to methodological flaws or lack of available data However only one reported a significant result for the outcome of symptomatic UTIs Side effects were common in all trials and dropoutswithdrawals in several of the trials were highAuthors conclusions There is some evidence from two good quality RCTs that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period in women If it is effective for other groups such as children and elderly men and women is not clear The large number of dropoutswithdrawals from some of the trials indicates that cranberry juice may not be acceptable over long periods of time In addition it is not clear what is the optimum dosage or method of administration (eg juice or tablets) Further properly designed trials with relevant outcomes are needed

Meta-analysis

Examines a group of valid studies on a topic

Combines results using accepted statistical methodology to reach a consensus on the overall results

Linde K Berner M Egger M Mulrow CSt Johns wort for depression meta-analysis of randomised controlled trials Br J Psychiatry 2005 Feb18699-107

BACKGROUND Extracts of Hypericum perforatum (St Johns wort) are widely used to treat depression Evidence for its efficacy has been criticised on methodological grounds AIMS To update evidence from randomised trials regarding the effectiveness of Hypericum extracts METHODS We performed a systematic review and meta-analysis of 37 double-blind randomised controlled trials that compared clinical effects of Hypericum monopreparation with either placebo or a standard antidepressant in adults with depressive disorders RESULTS Larger placebo-controlled trials restricted to patients with major depression showed only minor effects over placebo while older and smaller trials not restricted to patients with major depression showed marked effects Compared with standard antidepressants Hypericum extracts had similar effects CONCLUSIONS Current evidence regarding Hypericum extracts is inconsistent and confusing In patients who meet criteria for major depression several recent placebo-controlled trials suggest that Hypericum has minimal beneficial effects while other trials suggest that Hypericum and standard antidepressants have similar beneficial effects

Levels of evidence

Level I obtained from at least one properly controlled randomized trial considered the gold standard of evidence

Level II-1derived from controlled trials without randomization

Level II-2 well-designed cohort or case-control studies

Level II-3 includes studies with external control groups or ecological studies

Level III evidence is derived from reports of expert committees not because it is weaker than levels I or II but because it is often difficult to ascertain the scientific origin of the committee opinion

Evidence Pyramid

Case SeriesCase Reports

Case Control Studies

Cohort Studies

Randomized Controlled Trial

Systematic Review

Meta-analysis

Animal Research

Type of Question Suggested Best Type of Study

Therapy RCT gt cohort gt case control gt case series

Diagnosis Prospective blind comparison to gold standard

Etiology Harm RCT gt cohort gt case control gt case series

Prognosis Cohort study gt case control gt case series

Prevention RCT gt cohort study gt case control gt case series

Clinical Exam Prospective blind comparison to gold standard

Cost Economic analysis

Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic review

QuestionIn adult with acute maxillary sinusitis does a 3-day course of trimethoprim-sulfamethoxazole yield the same cure rates as a 10-day course with fewer adverse effects and costs

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

Type of question Type of study

TherapyRCTgtcohortgtcase controlgt case series

A 42-year old woman presented at the emergency room of the hospital complaining of muscle pain and tiredness She was found to have hyperventilation and weakness of four limbs with muscle power of grade 5( )5 All her symptoms gradually subsided over the next few hours History revealed she was taking maqianzi a herbal remedy for neck pain Could this herbal supplement have caused her problems In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn an adult woman does maqianzi cause muscle pain and tiredness

Type of question Type of study

Etiology RCTgtcohortgtcase controlgt case series

You have heard that kidney yin deficiency is a valid tool to diagnose postmenopausal women with vasomotor symptoms You need to find further information on this test

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn a postmenopausal woman is kidney yin deficiency as effective as standard tools in diagnosis of vasomotor symptoms

Type of question Type of study

Diagnosis Prospective blind comparison to gold standard

SystemsComputerized

decision support

SummariesDynamed UptoDate PIER

Clinical Evidence EBM guidelinesSynopses

TRIP ACP Journal Club

SynthesesCochrane Systematic

Reviews DARE

StudiesPubMed CINAHL Scopus

Adapted from Haynes (2001)

Haynes RB Of studies summaries synopses and systems the ldquo5S evolution of services for finding current best evidence ACP Journal Club 2001134 A11ndash13

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
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• Slide 15
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• Slide 23
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• Slide 25
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• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

Jepson RG Mihaljevic L Craig J Cranberries for preventing urinary tract infections The Cochrane Database of Systematic Reviews 2004 Issue 2 Background Cranberries (particularly in the form of cranberry juice) have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs) The aim of this review is to assess the effectiveness of cranberries in preventing such infectionsObjectives To assess the effectiveness of cranberry juice and other cranberry products in preventing UTIs in susceptible populationsSearch strategy Electronic databases and the Internet were searched using English and non English language terms companies involved with the promotion and distribution of cranberry preparations were contacted reference lists of review articles and relevant trials were searchedhellipsearched in February 2003Selection criteria All randomised or quasi randomised controlled trials of cranberry juiceproducts for the prevention of urinary tract infections in susceptible populations Trials of men women or children were includedData collection and analysis Two reviewers independently assessed and extracted information Information was collected on methods participants interventions and outcomes (urinary tract infections (symptomatic and asymptomatic) side effects and adherence to therapy) RR were calculated where appropriate otherwise a narrative synthesis was undertaken Quality was assessed using the Cochrane criteriaMain results Seven trials met the inclusion criteria (four cross-over three parallel group) The effectiveness of cranberry juice (or cranberry-lingonberry juice) versus placebo juice or water was evaluated in six trials and the effectiveness of cranberries tablets versus placebo was evaluated in two trials (one study evaluated both juice and tablets) In two good quality RCTs cranberry products significantly reduced the incidence of UTIs at twelve months (RR 061 95 CI040 to 091) compared with placebocontrol in women One trial gave 75 g cranberry concentrate daily (in 50 ml) the other gave 130 concentrate given either in 250 ml juice or in tablet form There was no significant difference in the incidence of UTIs between cranberry juice versus cranberry capsules (RR 111 95 CI049 to 250) Five trials were not included in the meta-analyses due to methodological flaws or lack of available data However only one reported a significant result for the outcome of symptomatic UTIs Side effects were common in all trials and dropoutswithdrawals in several of the trials were highAuthors conclusions There is some evidence from two good quality RCTs that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period in women If it is effective for other groups such as children and elderly men and women is not clear The large number of dropoutswithdrawals from some of the trials indicates that cranberry juice may not be acceptable over long periods of time In addition it is not clear what is the optimum dosage or method of administration (eg juice or tablets) Further properly designed trials with relevant outcomes are needed

Meta-analysis

Examines a group of valid studies on a topic

Combines results using accepted statistical methodology to reach a consensus on the overall results

Linde K Berner M Egger M Mulrow CSt Johns wort for depression meta-analysis of randomised controlled trials Br J Psychiatry 2005 Feb18699-107

BACKGROUND Extracts of Hypericum perforatum (St Johns wort) are widely used to treat depression Evidence for its efficacy has been criticised on methodological grounds AIMS To update evidence from randomised trials regarding the effectiveness of Hypericum extracts METHODS We performed a systematic review and meta-analysis of 37 double-blind randomised controlled trials that compared clinical effects of Hypericum monopreparation with either placebo or a standard antidepressant in adults with depressive disorders RESULTS Larger placebo-controlled trials restricted to patients with major depression showed only minor effects over placebo while older and smaller trials not restricted to patients with major depression showed marked effects Compared with standard antidepressants Hypericum extracts had similar effects CONCLUSIONS Current evidence regarding Hypericum extracts is inconsistent and confusing In patients who meet criteria for major depression several recent placebo-controlled trials suggest that Hypericum has minimal beneficial effects while other trials suggest that Hypericum and standard antidepressants have similar beneficial effects

Levels of evidence

Level I obtained from at least one properly controlled randomized trial considered the gold standard of evidence

Level II-1derived from controlled trials without randomization

Level II-2 well-designed cohort or case-control studies

Level II-3 includes studies with external control groups or ecological studies

Level III evidence is derived from reports of expert committees not because it is weaker than levels I or II but because it is often difficult to ascertain the scientific origin of the committee opinion

Evidence Pyramid

Case SeriesCase Reports

Case Control Studies

Cohort Studies

Randomized Controlled Trial

Systematic Review

Meta-analysis

Animal Research

Type of Question Suggested Best Type of Study

Therapy RCT gt cohort gt case control gt case series

Diagnosis Prospective blind comparison to gold standard

Etiology Harm RCT gt cohort gt case control gt case series

Prognosis Cohort study gt case control gt case series

Prevention RCT gt cohort study gt case control gt case series

Clinical Exam Prospective blind comparison to gold standard

Cost Economic analysis

Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic review

QuestionIn adult with acute maxillary sinusitis does a 3-day course of trimethoprim-sulfamethoxazole yield the same cure rates as a 10-day course with fewer adverse effects and costs

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

Type of question Type of study

TherapyRCTgtcohortgtcase controlgt case series

A 42-year old woman presented at the emergency room of the hospital complaining of muscle pain and tiredness She was found to have hyperventilation and weakness of four limbs with muscle power of grade 5( )5 All her symptoms gradually subsided over the next few hours History revealed she was taking maqianzi a herbal remedy for neck pain Could this herbal supplement have caused her problems In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn an adult woman does maqianzi cause muscle pain and tiredness

Type of question Type of study

Etiology RCTgtcohortgtcase controlgt case series

You have heard that kidney yin deficiency is a valid tool to diagnose postmenopausal women with vasomotor symptoms You need to find further information on this test

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn a postmenopausal woman is kidney yin deficiency as effective as standard tools in diagnosis of vasomotor symptoms

Type of question Type of study

Diagnosis Prospective blind comparison to gold standard

SystemsComputerized

decision support

SummariesDynamed UptoDate PIER

Clinical Evidence EBM guidelinesSynopses

TRIP ACP Journal Club

SynthesesCochrane Systematic

Reviews DARE

StudiesPubMed CINAHL Scopus

Adapted from Haynes (2001)

Haynes RB Of studies summaries synopses and systems the ldquo5S evolution of services for finding current best evidence ACP Journal Club 2001134 A11ndash13

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
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• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

Meta-analysis

Examines a group of valid studies on a topic

Combines results using accepted statistical methodology to reach a consensus on the overall results

Linde K Berner M Egger M Mulrow CSt Johns wort for depression meta-analysis of randomised controlled trials Br J Psychiatry 2005 Feb18699-107

BACKGROUND Extracts of Hypericum perforatum (St Johns wort) are widely used to treat depression Evidence for its efficacy has been criticised on methodological grounds AIMS To update evidence from randomised trials regarding the effectiveness of Hypericum extracts METHODS We performed a systematic review and meta-analysis of 37 double-blind randomised controlled trials that compared clinical effects of Hypericum monopreparation with either placebo or a standard antidepressant in adults with depressive disorders RESULTS Larger placebo-controlled trials restricted to patients with major depression showed only minor effects over placebo while older and smaller trials not restricted to patients with major depression showed marked effects Compared with standard antidepressants Hypericum extracts had similar effects CONCLUSIONS Current evidence regarding Hypericum extracts is inconsistent and confusing In patients who meet criteria for major depression several recent placebo-controlled trials suggest that Hypericum has minimal beneficial effects while other trials suggest that Hypericum and standard antidepressants have similar beneficial effects

Levels of evidence

Level I obtained from at least one properly controlled randomized trial considered the gold standard of evidence

Level II-1derived from controlled trials without randomization

Level II-2 well-designed cohort or case-control studies

Level II-3 includes studies with external control groups or ecological studies

Level III evidence is derived from reports of expert committees not because it is weaker than levels I or II but because it is often difficult to ascertain the scientific origin of the committee opinion

Evidence Pyramid

Case SeriesCase Reports

Case Control Studies

Cohort Studies

Randomized Controlled Trial

Systematic Review

Meta-analysis

Animal Research

Type of Question Suggested Best Type of Study

Therapy RCT gt cohort gt case control gt case series

Diagnosis Prospective blind comparison to gold standard

Etiology Harm RCT gt cohort gt case control gt case series

Prognosis Cohort study gt case control gt case series

Prevention RCT gt cohort study gt case control gt case series

Clinical Exam Prospective blind comparison to gold standard

Cost Economic analysis

Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic review

QuestionIn adult with acute maxillary sinusitis does a 3-day course of trimethoprim-sulfamethoxazole yield the same cure rates as a 10-day course with fewer adverse effects and costs

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

Type of question Type of study

TherapyRCTgtcohortgtcase controlgt case series

A 42-year old woman presented at the emergency room of the hospital complaining of muscle pain and tiredness She was found to have hyperventilation and weakness of four limbs with muscle power of grade 5( )5 All her symptoms gradually subsided over the next few hours History revealed she was taking maqianzi a herbal remedy for neck pain Could this herbal supplement have caused her problems In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn an adult woman does maqianzi cause muscle pain and tiredness

Type of question Type of study

Etiology RCTgtcohortgtcase controlgt case series

You have heard that kidney yin deficiency is a valid tool to diagnose postmenopausal women with vasomotor symptoms You need to find further information on this test

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn a postmenopausal woman is kidney yin deficiency as effective as standard tools in diagnosis of vasomotor symptoms

Type of question Type of study

Diagnosis Prospective blind comparison to gold standard

SystemsComputerized

decision support

SummariesDynamed UptoDate PIER

Clinical Evidence EBM guidelinesSynopses

TRIP ACP Journal Club

SynthesesCochrane Systematic

Reviews DARE

StudiesPubMed CINAHL Scopus

Adapted from Haynes (2001)

Haynes RB Of studies summaries synopses and systems the ldquo5S evolution of services for finding current best evidence ACP Journal Club 2001134 A11ndash13

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
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• Slide 51
• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

Linde K Berner M Egger M Mulrow CSt Johns wort for depression meta-analysis of randomised controlled trials Br J Psychiatry 2005 Feb18699-107

BACKGROUND Extracts of Hypericum perforatum (St Johns wort) are widely used to treat depression Evidence for its efficacy has been criticised on methodological grounds AIMS To update evidence from randomised trials regarding the effectiveness of Hypericum extracts METHODS We performed a systematic review and meta-analysis of 37 double-blind randomised controlled trials that compared clinical effects of Hypericum monopreparation with either placebo or a standard antidepressant in adults with depressive disorders RESULTS Larger placebo-controlled trials restricted to patients with major depression showed only minor effects over placebo while older and smaller trials not restricted to patients with major depression showed marked effects Compared with standard antidepressants Hypericum extracts had similar effects CONCLUSIONS Current evidence regarding Hypericum extracts is inconsistent and confusing In patients who meet criteria for major depression several recent placebo-controlled trials suggest that Hypericum has minimal beneficial effects while other trials suggest that Hypericum and standard antidepressants have similar beneficial effects

Levels of evidence

Level I obtained from at least one properly controlled randomized trial considered the gold standard of evidence

Level II-1derived from controlled trials without randomization

Level II-2 well-designed cohort or case-control studies

Level II-3 includes studies with external control groups or ecological studies

Level III evidence is derived from reports of expert committees not because it is weaker than levels I or II but because it is often difficult to ascertain the scientific origin of the committee opinion

Evidence Pyramid

Case SeriesCase Reports

Case Control Studies

Cohort Studies

Randomized Controlled Trial

Systematic Review

Meta-analysis

Animal Research

Type of Question Suggested Best Type of Study

Therapy RCT gt cohort gt case control gt case series

Diagnosis Prospective blind comparison to gold standard

Etiology Harm RCT gt cohort gt case control gt case series

Prognosis Cohort study gt case control gt case series

Prevention RCT gt cohort study gt case control gt case series

Clinical Exam Prospective blind comparison to gold standard

Cost Economic analysis

Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic review

QuestionIn adult with acute maxillary sinusitis does a 3-day course of trimethoprim-sulfamethoxazole yield the same cure rates as a 10-day course with fewer adverse effects and costs

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

Type of question Type of study

TherapyRCTgtcohortgtcase controlgt case series

A 42-year old woman presented at the emergency room of the hospital complaining of muscle pain and tiredness She was found to have hyperventilation and weakness of four limbs with muscle power of grade 5( )5 All her symptoms gradually subsided over the next few hours History revealed she was taking maqianzi a herbal remedy for neck pain Could this herbal supplement have caused her problems In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn an adult woman does maqianzi cause muscle pain and tiredness

Type of question Type of study

Etiology RCTgtcohortgtcase controlgt case series

You have heard that kidney yin deficiency is a valid tool to diagnose postmenopausal women with vasomotor symptoms You need to find further information on this test

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn a postmenopausal woman is kidney yin deficiency as effective as standard tools in diagnosis of vasomotor symptoms

Type of question Type of study

Diagnosis Prospective blind comparison to gold standard

SystemsComputerized

decision support

SummariesDynamed UptoDate PIER

Clinical Evidence EBM guidelinesSynopses

TRIP ACP Journal Club

SynthesesCochrane Systematic

Reviews DARE

StudiesPubMed CINAHL Scopus

Adapted from Haynes (2001)

Haynes RB Of studies summaries synopses and systems the ldquo5S evolution of services for finding current best evidence ACP Journal Club 2001134 A11ndash13

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• Slide 36
• Slide 37
• Slide 38
• Slide 39
• Slide 43
• Slide 45
• Slide 47
• Slide 49
• Slide 51
• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

Levels of evidence

Level I obtained from at least one properly controlled randomized trial considered the gold standard of evidence

Level II-1derived from controlled trials without randomization

Level II-2 well-designed cohort or case-control studies

Level II-3 includes studies with external control groups or ecological studies

Level III evidence is derived from reports of expert committees not because it is weaker than levels I or II but because it is often difficult to ascertain the scientific origin of the committee opinion

Evidence Pyramid

Case SeriesCase Reports

Case Control Studies

Cohort Studies

Randomized Controlled Trial

Systematic Review

Meta-analysis

Animal Research

Type of Question Suggested Best Type of Study

Therapy RCT gt cohort gt case control gt case series

Diagnosis Prospective blind comparison to gold standard

Etiology Harm RCT gt cohort gt case control gt case series

Prognosis Cohort study gt case control gt case series

Prevention RCT gt cohort study gt case control gt case series

Clinical Exam Prospective blind comparison to gold standard

Cost Economic analysis

Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic review

QuestionIn adult with acute maxillary sinusitis does a 3-day course of trimethoprim-sulfamethoxazole yield the same cure rates as a 10-day course with fewer adverse effects and costs

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

Type of question Type of study

TherapyRCTgtcohortgtcase controlgt case series

A 42-year old woman presented at the emergency room of the hospital complaining of muscle pain and tiredness She was found to have hyperventilation and weakness of four limbs with muscle power of grade 5( )5 All her symptoms gradually subsided over the next few hours History revealed she was taking maqianzi a herbal remedy for neck pain Could this herbal supplement have caused her problems In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn an adult woman does maqianzi cause muscle pain and tiredness

Type of question Type of study

Etiology RCTgtcohortgtcase controlgt case series

You have heard that kidney yin deficiency is a valid tool to diagnose postmenopausal women with vasomotor symptoms You need to find further information on this test

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn a postmenopausal woman is kidney yin deficiency as effective as standard tools in diagnosis of vasomotor symptoms

Type of question Type of study

Diagnosis Prospective blind comparison to gold standard

SystemsComputerized

decision support

SummariesDynamed UptoDate PIER

Clinical Evidence EBM guidelinesSynopses

TRIP ACP Journal Club

SynthesesCochrane Systematic

Reviews DARE

StudiesPubMed CINAHL Scopus

Adapted from Haynes (2001)

Haynes RB Of studies summaries synopses and systems the ldquo5S evolution of services for finding current best evidence ACP Journal Club 2001134 A11ndash13

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• Slide 36
• Slide 37
• Slide 38
• Slide 39
• Slide 43
• Slide 45
• Slide 47
• Slide 49
• Slide 51
• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

Evidence Pyramid

Case SeriesCase Reports

Case Control Studies

Cohort Studies

Randomized Controlled Trial

Systematic Review

Meta-analysis

Animal Research

Type of Question Suggested Best Type of Study

Therapy RCT gt cohort gt case control gt case series

Diagnosis Prospective blind comparison to gold standard

Etiology Harm RCT gt cohort gt case control gt case series

Prognosis Cohort study gt case control gt case series

Prevention RCT gt cohort study gt case control gt case series

Clinical Exam Prospective blind comparison to gold standard

Cost Economic analysis

Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic review

QuestionIn adult with acute maxillary sinusitis does a 3-day course of trimethoprim-sulfamethoxazole yield the same cure rates as a 10-day course with fewer adverse effects and costs

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

Type of question Type of study

TherapyRCTgtcohortgtcase controlgt case series

A 42-year old woman presented at the emergency room of the hospital complaining of muscle pain and tiredness She was found to have hyperventilation and weakness of four limbs with muscle power of grade 5( )5 All her symptoms gradually subsided over the next few hours History revealed she was taking maqianzi a herbal remedy for neck pain Could this herbal supplement have caused her problems In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn an adult woman does maqianzi cause muscle pain and tiredness

Type of question Type of study

Etiology RCTgtcohortgtcase controlgt case series

You have heard that kidney yin deficiency is a valid tool to diagnose postmenopausal women with vasomotor symptoms You need to find further information on this test

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn a postmenopausal woman is kidney yin deficiency as effective as standard tools in diagnosis of vasomotor symptoms

Type of question Type of study

Diagnosis Prospective blind comparison to gold standard

SystemsComputerized

decision support

SummariesDynamed UptoDate PIER

Clinical Evidence EBM guidelinesSynopses

TRIP ACP Journal Club

SynthesesCochrane Systematic

Reviews DARE

StudiesPubMed CINAHL Scopus

Adapted from Haynes (2001)

Haynes RB Of studies summaries synopses and systems the ldquo5S evolution of services for finding current best evidence ACP Journal Club 2001134 A11ndash13

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• Slide 36
• Slide 37
• Slide 38
• Slide 39
• Slide 43
• Slide 45
• Slide 47
• Slide 49
• Slide 51
• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

Type of Question Suggested Best Type of Study

Therapy RCT gt cohort gt case control gt case series

Diagnosis Prospective blind comparison to gold standard

Etiology Harm RCT gt cohort gt case control gt case series

Prognosis Cohort study gt case control gt case series

Prevention RCT gt cohort study gt case control gt case series

Clinical Exam Prospective blind comparison to gold standard

Cost Economic analysis

Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic review

QuestionIn adult with acute maxillary sinusitis does a 3-day course of trimethoprim-sulfamethoxazole yield the same cure rates as a 10-day course with fewer adverse effects and costs

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

Type of question Type of study

TherapyRCTgtcohortgtcase controlgt case series

A 42-year old woman presented at the emergency room of the hospital complaining of muscle pain and tiredness She was found to have hyperventilation and weakness of four limbs with muscle power of grade 5( )5 All her symptoms gradually subsided over the next few hours History revealed she was taking maqianzi a herbal remedy for neck pain Could this herbal supplement have caused her problems In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn an adult woman does maqianzi cause muscle pain and tiredness

Type of question Type of study

Etiology RCTgtcohortgtcase controlgt case series

You have heard that kidney yin deficiency is a valid tool to diagnose postmenopausal women with vasomotor symptoms You need to find further information on this test

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn a postmenopausal woman is kidney yin deficiency as effective as standard tools in diagnosis of vasomotor symptoms

Type of question Type of study

Diagnosis Prospective blind comparison to gold standard

SystemsComputerized

decision support

SummariesDynamed UptoDate PIER

Clinical Evidence EBM guidelinesSynopses

TRIP ACP Journal Club

SynthesesCochrane Systematic

Reviews DARE

StudiesPubMed CINAHL Scopus

Adapted from Haynes (2001)

Haynes RB Of studies summaries synopses and systems the ldquo5S evolution of services for finding current best evidence ACP Journal Club 2001134 A11ndash13

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
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• Slide 14
• Slide 15
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• Slide 59
• Slide 65
• Best Type of Study for Your Question

QuestionIn adult with acute maxillary sinusitis does a 3-day course of trimethoprim-sulfamethoxazole yield the same cure rates as a 10-day course with fewer adverse effects and costs

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

Type of question Type of study

TherapyRCTgtcohortgtcase controlgt case series

A 42-year old woman presented at the emergency room of the hospital complaining of muscle pain and tiredness She was found to have hyperventilation and weakness of four limbs with muscle power of grade 5( )5 All her symptoms gradually subsided over the next few hours History revealed she was taking maqianzi a herbal remedy for neck pain Could this herbal supplement have caused her problems In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn an adult woman does maqianzi cause muscle pain and tiredness

Type of question Type of study

Etiology RCTgtcohortgtcase controlgt case series

You have heard that kidney yin deficiency is a valid tool to diagnose postmenopausal women with vasomotor symptoms You need to find further information on this test

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn a postmenopausal woman is kidney yin deficiency as effective as standard tools in diagnosis of vasomotor symptoms

Type of question Type of study

Diagnosis Prospective blind comparison to gold standard

SystemsComputerized

decision support

SummariesDynamed UptoDate PIER

Clinical Evidence EBM guidelinesSynopses

TRIP ACP Journal Club

SynthesesCochrane Systematic

Reviews DARE

StudiesPubMed CINAHL Scopus

Adapted from Haynes (2001)

Haynes RB Of studies summaries synopses and systems the ldquo5S evolution of services for finding current best evidence ACP Journal Club 2001134 A11ndash13

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
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• Slide 28
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• Slide 36
• Slide 37
• Slide 38
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• Slide 47
• Slide 49
• Slide 51
• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

A 42-year old woman presented at the emergency room of the hospital complaining of muscle pain and tiredness She was found to have hyperventilation and weakness of four limbs with muscle power of grade 5( )5 All her symptoms gradually subsided over the next few hours History revealed she was taking maqianzi a herbal remedy for neck pain Could this herbal supplement have caused her problems In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn an adult woman does maqianzi cause muscle pain and tiredness

Type of question Type of study

Etiology RCTgtcohortgtcase controlgt case series

You have heard that kidney yin deficiency is a valid tool to diagnose postmenopausal women with vasomotor symptoms You need to find further information on this test

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn a postmenopausal woman is kidney yin deficiency as effective as standard tools in diagnosis of vasomotor symptoms

Type of question Type of study

Diagnosis Prospective blind comparison to gold standard

SystemsComputerized

decision support

SummariesDynamed UptoDate PIER

Clinical Evidence EBM guidelinesSynopses

TRIP ACP Journal Club

SynthesesCochrane Systematic

Reviews DARE

StudiesPubMed CINAHL Scopus

Adapted from Haynes (2001)

Haynes RB Of studies summaries synopses and systems the ldquo5S evolution of services for finding current best evidence ACP Journal Club 2001134 A11ndash13

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• Slide 36
• Slide 37
• Slide 38
• Slide 39
• Slide 43
• Slide 45
• Slide 47
• Slide 49
• Slide 51
• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

You have heard that kidney yin deficiency is a valid tool to diagnose postmenopausal women with vasomotor symptoms You need to find further information on this test

In patient with

[Patient Problem]

does

[Intervention]

or

[Comparison if any]

affect

[Outcome]

QuestionIn a postmenopausal woman is kidney yin deficiency as effective as standard tools in diagnosis of vasomotor symptoms

Type of question Type of study

Diagnosis Prospective blind comparison to gold standard

SystemsComputerized

decision support

SummariesDynamed UptoDate PIER

Clinical Evidence EBM guidelinesSynopses

TRIP ACP Journal Club

SynthesesCochrane Systematic

Reviews DARE

StudiesPubMed CINAHL Scopus

Adapted from Haynes (2001)

Haynes RB Of studies summaries synopses and systems the ldquo5S evolution of services for finding current best evidence ACP Journal Club 2001134 A11ndash13

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
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• Slide 26
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• Slide 37
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• Slide 49
• Slide 51
• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

SystemsComputerized

decision support

SummariesDynamed UptoDate PIER

Clinical Evidence EBM guidelinesSynopses

TRIP ACP Journal Club

SynthesesCochrane Systematic

Reviews DARE

StudiesPubMed CINAHL Scopus

Adapted from Haynes (2001)

Haynes RB Of studies summaries synopses and systems the ldquo5S evolution of services for finding current best evidence ACP Journal Club 2001134 A11ndash13

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
• Slide 24
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• Slide 49
• Slide 51
• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

Original Studies

If an original study is your best optionhelliphellip

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
• Slide 24
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• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Slide 30
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• Best Type of Study for Your Question

IMRAD format

Introduction why the authors decided to conduct the research

Methods how they conducted the research and analyzed their results

Results what was foundAnd

Discussion what the authors think the results mean

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

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• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

PP-ICONS

Problem Patient or population Intervention Comparison Outcome Number of subjects Statistics

Flaherty Robert J A simple method for evaluating the clinical literature Fam Prac Mgt May 200447-52 Available online at

httpwwwaafporgfpm2004050047asimhtml

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
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• Slide 51
• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

Scenario

You just saw a nine-year old patient with common warts on her hands She is an ideal candidate for cryotherapy Her mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Slide 26
• Slide 27
• Slide 28
• Slide 29
• Slide 30
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• Slide 43
• Slide 45
• Slide 47
• Slide 49
• Slide 51
• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

Clinical question

What is your clinical question

ldquo ldquoIn children with warts is duct In children with warts is duct tape as effective as cryotherapy tape as effective as cryotherapy in eliminating the wartin eliminating the wart

PICO Patient PICO Patient InterventionComparison OutcomeInterventionComparison Outcome

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

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• Best Type of Study for Your Question

Search

After you have your clinical question search the appropriate databases Dynamed PIER UpToDate Cochrane

Clinical Evidence PubMed

Focht DR 3rd Spicer C Fairchok MPFocht DR 3rd Spicer C Fairchok MPThe efficacy of duct tape vs The efficacy of duct tape vs cryotherapy in the treatment of cryotherapy in the treatment of verruca vulgaris (the common wart) verruca vulgaris (the common wart) Arch Pediatr Adolesc Med 2002 Arch Pediatr Adolesc Med 2002 Oct156(10)971-4 Oct156(10)971-4

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
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• Slide 10
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• Best Type of Study for Your Question

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

DESIGN A prospective randomized controlled trial with 2 treatment arms for warts in children

SETTING The general pediatric and adolescent clinics at a military medical center

PATIENTS A total of 61 patients (age range 3-22 years) were enrolled in the study from October 31 2000 to July 25 2001 51 patients completed the study and were available for analysis

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months Patients had their warts measured at baseline and with return visits

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

RESULTS Of the 51 patients completing the study 26 (51) were treated with duct tape and 25 (49) were treated with cryotherapy Twenty-two patients (85) in the duct tape arm vs 15 patients (60) enrolled in the cryotherapy arm had complete resolution of their warts (P =05 by chi(2) analysis) The majority of warts that responded to either therapy did so within the first month of treatment

CONCLUSION Duct tape occlusion therapy was significantly more effective than cryotherapy for treatment of the common wart

Abstract

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
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• Slide 58
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• Slide 65
• Best Type of Study for Your Question

Problem (PP-ICONS)

What is the clinical condition that was studied in the article

OBJECTIVE To determine if application of duct tape is as effective as cryotherapy in the treatment of common warts

The problem studied should be sufficiently similar to your clinical problem or the results will not be relevant

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

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• Best Type of Study for Your Question

Patient or Population (PP-ICONS)

Is the study group similar to your patient or practice

SETTING The general pediatric and adolescent clinics at a military medical center PATIENTS A total of 61 patients (age range 3-22 years)

If the patients in the study are not If the patients in the study are not similar to your patient (older sicker similar to your patient (older sicker different gender or more clinically different gender or more clinically complicated) the results may not be complicated) the results may not be relevantrelevant

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

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• Best Type of Study for Your Question

Intervention (PP-ICONS)

Is the intervention the same as what you are looking for

Could be a diagnostic test or a Could be a diagnostic test or a treatmenttreatment

The patientrsquos mother has heard about treating warts with duct tape and wants to know if you would recommend this treatment

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
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• Slide 65
• Best Type of Study for Your Question

Comparison (PP-ICONS)

The comparison is what the treatment is tested against

Could be a different diagnostic test Could be a different diagnostic test another therapy placebo or no another therapy placebo or no treatment at alltreatment at all

INTERVENTION Patients were randomized using computer-generated codes to receive either cryotherapy (liquid nitrogen applied to each wart for 10 seconds every 2-3 weeks) for a maximum of 6 treatments or duct tape occlusion (applied directly to the wart) for a maximum of 2 months

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
• Slide 24
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• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

Outcome (PP-ICONS)

Disease-oriented outcomes (DOEs) usually reflect changes in physiologic parameters It has long been assumed that improving It has long been assumed that improving

the physiologic parameters of a disease will the physiologic parameters of a disease will result in a better outcome but this is not result in a better outcome but this is not always truealways true Patient-oriented evidence that matters Patient-oriented evidence that matters

(POEMs) look at outcomes such as (POEMs) look at outcomes such as morbidity mortality and cost morbidity mortality and cost

Therefore DOEs are interesting but of Therefore DOEs are interesting but of questionable relevance whereas POEMs questionable relevance whereas POEMs are very interesting and very relevantare very interesting and very relevant

MAIN OUTCOME MEASURE Complete resolution of the wart being studied

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

• Slide 4
• Slide 8
• Slide 10
• Slide 11
• Slide 14
• Slide 15
• Slide 16
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
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• Slide 28
• Slide 29
• Slide 30
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• Slide 37
• Slide 38
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• Slide 45
• Slide 47
• Slide 49
• Slide 51
• Slide 53
• Slide 54
• Slide 55
• Slide 56
• Slide 57
• Slide 58
• Slide 59
• Slide 65
• Best Type of Study for Your Question

Number (PP-ICONS)

Number of subjects in the study is crucial in whether accurate statistics can be generated from the data Too few patients may not be enough to Too few patients may not be enough to

show that a difference really exists between show that a difference really exists between intervention and comparison groups (power intervention and comparison groups (power of a study)of a study) Many studies contain lt100 subjects which Many studies contain lt100 subjects which is usually inadequate to provide reliable is usually inadequate to provide reliable statisticsstatistics Good rule of thumb ndash 400 subjects neededGood rule of thumb ndash 400 subjects needed

Krejcie RV Morgan DW Determining sample size for research activities Educational and Psychological Measurements 197030607-610

51 patients completed the study

Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

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Statistics (PP-ICONS) Relative risk reduction (RRR) the

percent reduction in events in the treated group compared to the control group event rate Not a good way to compare outcomesNot a good way to compare outcomes

Amplifies small differences and makes Amplifies small differences and makes insignificant findings appear significantinsignificant findings appear significant

Doesnrsquot reflect the baseline risk of the outcome Doesnrsquot reflect the baseline risk of the outcome eventevent Can make weak results look good thereforeCan make weak results look good therefore

Popular and will be reported in almost every Popular and will be reported in almost every journal articlejournal article Ignore ndash it can mislead youIgnore ndash it can mislead you

RRR would be (85 percent ndash 60 percent60 percent x 100 = 42 percent

Ie 42 percent more effective than cryotherapy in treating warts

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

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• Best Type of Study for Your Question

Statistics (PP-ICONS) Absolute risk reduction (ARR) the

difference in the outcome event rate between the control group and the experimental group

A better statistic to evaluate A better statistic to evaluate outcome as it does not amplify small outcome as it does not amplify small differences but shows the true differences but shows the true difference between the experimental difference between the experimental and control interventionsand control interventions

ARR for the wart study is the outcome event rate (complete resolution of warts) for duct tape (85 percent) minus the outcome event rate for cryotherapy (60 percent) = 25 percent

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

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• Best Type of Study for Your Question

Statistics (PP-ICONS) Number needed to treat (NNT) number of

patients who must be treated to prevent one adverse outcome OR the number of patients who must be treated for one patient to benefit Single most clinically useful statisticSingle most clinically useful statistic Easy to calculate simply the inverse of the ARREasy to calculate simply the inverse of the ARR

For the wart study the NNT is 125 percent = 1025 = 4

4 patients need to be treated with duct tape for one to benefit more than if treated by cryotherapy

The lower the NNT the better For primary The lower the NNT the better For primary therapies an NNT of 10 or less is good with less therapies an NNT of 10 or less is good with less than 5 being very goodthan 5 being very good

For preventive interventions the NNT will be For preventive interventions the NNT will be higher A NNT for prevention of less than 20 might higher A NNT for prevention of less than 20 might be particularly goodbe particularly good

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

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• Best Type of Study for Your Question

Intention to Treat Analysis Attrition Were patients lost to follow-up and

if so whyIntention to treat subjects are analyzed according to the categories into which they were originally randomized

ndash Benefits of a treatment are more difficult to demonstrate with intention-to-treat analysis

ndash Helps to mitigate differences by including subjects who are unlikely to have experienced benefit from the interventionSix patients from cryotherapy group and 4 patients from the duct tape group were lost to follow-up (16 of patients)Worst case scenario 6 cryotherapy patients had wart resolution and the 4 duct tape patients had residual wart Wart resolution would then be duct tape 78 and cryotherapy 68 (95 CI -17 to 28) ndash therefore not a statistically significant difference between the two treatments

Christakis DA Lehmann HP Is duct tape occlusion therapy as effective as cryotherapy for the treatment of the common wart Arch Pediatr Adolesc Med Oct 2002 vol 156 975-977

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

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• Best Type of Study for Your Question

Best Type of Study for Your Question

Type of QuestionType of Question Suggested Best Type of StudySuggested Best Type of Study

TherapyTherapy RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

DiagnosisDiagnosis Prospective blind comparison to gold standardProspective blind comparison to gold standard

Etiology HarmEtiology Harm RCT gt cohort gt case control gt case seriesRCT gt cohort gt case control gt case series

PrognosisPrognosis Cohort study gt case control gt case seriesCohort study gt case control gt case series

PreventionPrevention RCT gt cohort study gt case control gt case seriesRCT gt cohort study gt case control gt case series

Clinical ExamClinical Exam Prospective blind comparison to gold standardProspective blind comparison to gold standard

CostCost Economic analysisEconomic analysis

Questions of therapy etiology and prevention which can best be answered Questions of therapy etiology and prevention which can best be answered by RCT can also be answered by a meta-analysis or systematic reviewby RCT can also be answered by a meta-analysis or systematic review

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

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• Best Type of Study for Your Question

Assignment Identify a clinical problem with a patient Formulate a clinical question using PICO Search the literature for appropriate article(s) Evaluate the article(s) Complete the online assignment within two

weeks after date of lecture httpbiomedicallibrarysouthalabamaedulibrary

q=ebmrotationsassignment

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• Best Type of Study for Your Question