Systematic

searching in

Embase: Using

PICO to identify

relevant results

Dr. Ivan Krstić Product Development Manager Embase

18. XI 2015

2

In this webinar, we will discuss

- Concepts that form the basis of a PICO search strategy

- How to use information in Emtree to build effective searches

- The best levels of evidence to include in systematic reviews

- How upcoming Embase enhancements will make searching using

PICO even easier

3

Why is Evidence-Based Medicine Important?

“EBM solutions have the potential to accelerate and improve clinical decision

making and patient outcomes.”

To improve clinical efficiency/effectiveness

To apply proven practices in medicine

To standardize practices

To reduce unnecessary care/costs

"Evidence-based medicine is the thorough, explicit and cautious use of current

best evidence in making decisions about the care of individual patients."

4

EBM is a Life-Long, Problem-Based Learning Process

that Involves:

1. Clearly defining a clinically relevant question

2. Finding the best evidence

3. Critically appraising the evidence

4. Integrating the answer with clinical expertise and apply

5. Evaluating the treatment

“We’re doing our best every single day to connect the very latest research to clinical

care so that our patients can benefit as much as possible…. We use practice-based

evidence to achieve the very best outcomes for our patients…”

–– Steven E. Lipshultz, M.D., pediatrician-in-chief at the Children’s Hospital of Michigan and

chair of Pediatrics for the Wayne State University School of Medicine

5

EBM is on the Rise

“By the year 2020, 90% of clinical decisions will be supported by accurate,

timely, and current clinical information, and will reflect the best available

evidence”

–– Charter of the Institute of Medicine (IOM) Roundtable on Value & Science-Driven Health Care

Physicians to guide treatment decisions

Heathcare providers (insurers) to guide reimbursement policies

Governments to set guidelines and policy

Who uses EBM?

6

Finding the Best Evidence

What are Systematic Reviews?

High-level overviews of

primary research on a

particular research

question that tries to

identify, select, synthesize

and appraise all high-

quality research evidence

relevant to that question in

order to answer it.

“The systematic review provides a verdict on unsettled medical debates based on a painstaking

reassessment of all the relevant research…the impact can be enormous. Official guidelines and “best

practices” are established or changed after systematic reviews. Legal standards defining malpractice

may be set; insurers may decide which treatments to pay for and which to decline”.

7

Systematic reviews sum up the best available research on a specific question. This

is done by synthesizing the results of several studies.

A systematic review uses transparent procedures (defined in advance) to find,

evaluate and synthesize the results of relevant research. This practice is also

designed to minimize bias.

Peer review is a key part of the process; qualified independent researchers control

the author's methods and results.

A systematic review must have:

• Clear inclusion/ exclusion criteria

• An explicit search strategy

• Analysis of included studies

• Meta-analysis (where possible)

What is a systematic review?

8

Preparing a Systematic Review

The Cochrane Handbook outlines eight general steps for preparing a

systematic review:

1. Defining the review question(s) and developing criteria for including

studies

2. Searching for studies

3. Selecting studies and collecting data

4. Assessing risk of bias in included studies

5. Analyzing data and undertaking meta-analyses

6. Addressing reporting biases

7. Presenting results and "summary of findings" tables

8. Interpreting results and drawing conclusions

9

Using the PICO Framework to Structure a Question

P = Patient

I = Intervention

C = Comparison/control

O = Outcome

PICO is a method used to structure the elements (concepts) of the review question

into a search strategy and process.

On the next few slides, we’ll look at PICO to answer:

What are the best empirical antibiotic treatment options for bacterial meningitis?

10

P (Patient, Problem or Population)

A generic formula for this search strategy is:

1. Disease Emtree preferred term

‘name of the disease’/de

2. Disease term as free text search (Titles and Abstracts)

‘name of the disease’ OR ‘synonyms for the disease’

3. #1 OR #2

e.g.

'bacterial meningitis'/de OR

'bacterial meningitis' OR 'e. coli meningitis' OR 'escherichia coli meningitis' OR

'meningitis purulenta' OR 'purulent meningitis' OR 'pyogenic meningitis'

11

I (Intervention)

A generic formula for this search strategy is:

1. Drug Emtree preferred term

‘name of the drug’/de

2. Drug term as free text search

‘name of the drug’ OR ‘synonyms for the drug’

3. Include the Drug trade name (:tn) field, when appropriate

3. Drug CAS registry number Field search

‘CAS number’:rn

4. #1 OR #2 OR #3

e.g.

'antibiotic agent'/exp OR antibiotic*

12

C (Comparison or Control)

The aspects of this concept may include absence of risk or treatment,

placebo or alternative therapy. This component may not apply to all

review questions.

It does not apply in our example: “What are the best empirical antibiotic treatment options for bacterial

meningitis?”

13

O (Outcome)

The aspects of this concept may include risk, mortality, morbidity,

quality of life and utilities.

Sometimes this component is not searchable and/or it is advisable to

ignore it in the search process.

14

Logical Operators

Use the Boolean OR operator to search the relationship within each

individual concept.

The formula for using AND Boolean logical operators to search the

relationship between the concepts is:

P-elements

AND

I-elements

AND

C-elements

AND

O-elements

15

Poll – When you build systematic reviews do you:

• Create long multi-line queries

• Create short one-line queries and combine

• I don't do Systematic Reviews

16

Conduct a Scoping Search (to start)

Used to give an overview of previous work and to identify a Cochrane

review or systematic review in particular

– Can be conducted quite quickly

– Can be based on a simple search strategy

Limit topic search to Cochrane Review and/or Systematic Review

Note – Available on the Advanced, Drug and Disease search forms

17

Using Previous Work

If a Cochrane review or

systematic review is found, look

for a search strategy published

in the review.

When a search strategy is

provided:

– Assess its relevance for

adaptation

– Translate search syntax,

when necessary

– Consider indexed terms

(subject headings) and free-

text terms used

– Convert subject terms, where

needed

18

Hints and Tips for Searching

Always start with Emtree to identify a preferred term (subject

heading) for searching, when available

19

Reviewing an Emtree Record

Take note of any Synonyms

listed

Read the entry provided from

Dorland’s dictionary

e.g. Population:

'bacterial meningitis'/de OR 'bacterial

meningitis' OR 'e. coli meningitis' OR

'escherichia coli meningitis' OR 'meningitis

purulenta' OR 'purulent meningitis' OR

'pyogenic meningitis'

20

Hints and Tips for Searching

When performing an abstract and title search for any synonyms listed

in an Emtree record, consider using truncation or wildcard characters

(*, ?) as needed (e.g. antibiotic*)

When conducting a search of Article title and Abstract for author free-

text expressions consider using proximity operators (NEXT, NEAR)

as appropriate (e.g. meningitis NEAR/2 purulent*)

When performing free-text searches, remember to consider variant

spellings including British and American spellings and terminology

– e.g., tumor vs tumour; diaper vs nappy; pediatric vs paediatric;

otorhinolaryngology vs ear, nose and throat; overuse injury vs repetitive

strain injury

21

Limits

The most common type of search filter is for specific study designs

Other limits applied may include language, human or animal studies,

sex and age, publication type, year(s) of publication

When using date limits, remember also to add search strings for articles in press

and records in process

• Some articles in press do not have publication dates and will be lost if not search

for specifically!

22

Study Type Filters / Hedges

Common study design filters for systematic reviews include:

– RCTs

(randomised controlled trials or randomised clinical trials)

– Cohort studies

– Case-control studies

– Cross-sectional studies

Particular types of review questions are usually addressed by different

study designs.

For example,

http://hiru.mcmaster.ca/hiru/HIRU_Hedges_EMBASE_Strategies.aspx

suggests a therapy hedge that maximizes sensitivity:

random* OR (clinical NEXT/1 trial*) OR ‘health care quality’/exp

22

23

Review Questions and Study Designs

Type of Question Study Type

Etiology Cohort, Case-control

Therapy RCT

Prognosis Cohort

Harm Cohort, Case-control

Diagnosis Cross-sectional, Case-control

Economic Cost-effectiveness analysis, Resource utilization,

etc.

Note – Questions that can be answered best by RCT may be answered by

meta-analysis and systematic reviews also

23

24

Saving the Search

Use Save search for regular use of repeated search strategies

– e.g., study design, updating a search

– Or alternatively, set up an Email Alert

24

25

Share (Export) Records

Processing of records for data collection to evaluate and critically

appraise the evidence

– i.e., extraction, quality assessment and analysis based on inclusion and

exclusion criteria

25

26

Saving Records into Clipboard

Processing of records for data collection to evaluate and critically

appraise the evidence

– i.e., extraction, quality assessment and analysis based on inclusion and

exclusion criteria

26

27

Document the Search Process

Export the session history to copy and paste it into a document for

inclusion in any review documentation

– Or alternatively, email it

27

28

Summary of Search Processed

Remember to record the date the

search was processed

– If an update is needed, then

re-run the search using date

limits as well as search strings

for articles in press and

records in process

• Some articles in press do

not have publication dates

and will be lost if not

search for specifically!

28

29

Upcoming Embase enhancements will make

searching using PICO even easier

Thank you!

Any questions?

Contact:

Ivan Krstić i.krstic@elsevier.com

31

32

With Embase Critical Information isn’t Missed —

Includes all of MEDLINE (PubMed) Plus Much More

Embase

Embase

MEDLINE

• In-depth drug, disease, device indexing with >2x as many index terms as MEDLINE

• Unique search features to find results based on abstract and index terms and dozens of filters

• Ability to save, share and edit complex search strategies with a group

• Unique coverage of over 1.75m conference abstracts from >5,5000 conferences (added since 2009)

• Much more coverage of non-English content and RCTs

2,700 journals not available

on MEDLINE

Embase is Internationally Recognized and Recommended

Over 8,500 Journals/

30 Million Records!