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Cost-Effectiveness in Medicine

An Interactive Introduction

Jan J. v. Busschbach, Ph.D.Erasmus MC

• Institute for Medical Psychology and PsychotherapyViersprong Institute for studies on Personality Disorders

Presentations can be found at:www.busschbach.nl

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New cancer therapy

Symptoms Drug X Drug Y

Survival days 300 400

Days sick of chemotherapy 10 150

Days sick of disease 100 30

TWiST 190 220

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Time Without Symptoms of disease and subjective Toxic effects of treatment

TWiSTDeveloped by Richard Gelber (statistician)

In search for a typical “cancer” problemOften prolonged life but also a reductions in quality of

life

• At the beginning (side effects)

• At the endOnly count the days without symptoms of disease and

subjective toxic effects of the treatment

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TWiST in cancer therapy

0

20

40

60

80

100

120

140

160

180

1st Qtr 2nd Qtr 3rd Qtr 4th Qtr

First Year of treatment

Av

era

ge

nu

mb

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of

TW

iST

's

Drug

Placebo

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Fit new therapy in fixed budget

50 patients each year (per hospital) Drug x: 50 x euro 1.750 = euro 87.500 Drug y: 50 x euro 2.000 = euro 100.000

Drug budget for x or y = euro 50.000 Number of patient

• Drug x: euro 50.000 / 1.750 = 28.5 patients

• Drug y: euro 50.000 / 2.000 = 25.0 patients Survival in days

• Drug x: 28.5 patients x 300 days = 8.550 days

• Drug y: 25.0 patients x 400 days = 10.000 days Survival in TWiST

• Drug x: 28.5 patients x 190 TWiST = 5.415 days

• Drug y: 25.0 patients x 220 TWiST = 5.500 days

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TWiST: ignores differences in quality of life

TWiSTHealthy = 1Sick (dead) = 0

There is more to life than sick/healthMake intermediate valuesQ-TWiST

• Quality of life adjusted adjusted TWiST

How to scale quality of life?0.0

Quality

of life

1.0

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Quality of life

“…. Health is physical, mental and social well-being and not merely the absence of disease or infirmity...”

World Health Organization, 1947

Extending health to well-being: Quality of life What is the definition of quality of life?

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Definitions of Quality of Life Quality of life is the degree of need and satisfaction within the physical,

psychological, social, activity, material and structural area (Hörnquist, 1982). Quality of life is the subjective evaluation of good and satisfactory character of

life as a whole (De Haes, 1988). Health related quality of life is the subjective experiences or preferences

expressed by an individual, or members of a particular group of persons, in relation to specified aspects of health status that are meaningful, in definable ways, for that individual or group (Till, 1992).

Quality of life is a state of well-being which is a composite of two components: 1) the ability to perform everyday activities which reflects physical psychological, and social well-being and 2) patient satisfaction with levels of functioning and the control of disease and/or treatment related symptoms (Gotay et al., 1992).

An individual’s perception of their position in life in the context of the culture and values systems in which they live and in relation to their goals, expectations, standards and concerns (WHO Quality of life Groups, 1993).

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No clear definition because:…

Many possible definitionsResearchers are free to choose The notion of measuring the quality of life could include the

measurement of practically anything of interest to anybody. And, no doubt, everybody could find arguments supporting the selection of whichever set of indicators to be his choice

• (Andrews & Withy, 1976, page 6)

Different origins of researchClinical decision making:…

• does the patient benefit from the treatment?Epidemiology (public health):…

• what is the morbidity of the population?Health economics:…

• is it worth the money?

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Common items in definitions:

It is not the doctor who reports Quality of life is subjective….

“Given its inherently subjective nature, consensus was quickly reached that quality of life ratings should, whenever possible, be elicited directly from patients themselves. “ (Aaronson, in B Spilker (Ed): Quality of life and Pharmacoeconomics in Clinical Trails, 1996, page 180)

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Common items in definitions:

Health related Multidimensional

Physical, psychological, social

QuestionnairesStandardize questions and response

• Reproducible results: sciences

• Quantify subjectivity

Operational definedLike IQ and temperature.

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How to measure quality of life form a clinical point of view?

Choose itemsAre you able to walk one kilometer ?Do you feel depressed ?

Choose response modeBinary yes / noMultiple (Likert) yes / at bid / hardly / noContinuous (Visual Analogue Scale) Always ————X—— Never

Combine items to dimensions of quality of lifeSum up the items belonging to one dimensionRescale sum on a scale from 0 to 100

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SF-36

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SF-36

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Multidimensionality in outcomes in health care

What if outcome conflict…e.g: better mobility, but worse roll emotionalOn has to weight or combine outcomes

What if some patients dies?Cancer therapy

• Better quality of life, but higher mortality Weight quality of life with mortality

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Value a health state

WheelchairSome problems in walking aboutSome problems washing or dressingSome problems with performing usual activitiesSome pain or discomfortNo psychosocial problems

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Visual Analogue Scale

VASAlso called “category scaling”From psychological research

“How is your quality of life?” “X” marks the spot

Rescale to [0..1]

Different anchor point possible:Normal health (1.0) versus dead (0.0)Best imaginable health versus

worse imaginable health

Dead

Normal health

X

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EuroQol EQ-5D

MOBILITY I have no problems in walking about I have some problems in walking about I am confined to bed

SELF-CARE I have no problems with self-care I have some problems washing or dressing myself I am unable to wash or dress myself

USUAL ACTIVITIES (e.g. work, study, housework family or leisure activities)

I have no problems with performing my usual activities I have some problems with performing my usual activities I am unable to perform my usual activities

PAIN/DISCOMFORT I have no pain or discomfort I have moderate pain or discomfort I have extreme pain or discomfort

ANXIETY/DEPRESSION I am not anxious or depressed I am moderately anxious or depressed I am extremely anxious or depressed

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Ratio scale in QoL

If we want to weight dimensions of QoL…. Values should be (at least) on interval scale Is it possible?

My Qol is today twice as good as yesterday Her IQ is twice as high…This painting is twice as beautiful as…His depression is twice as… My lecture is twice as….

Is a VAS ratio or interval?

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Uni-dimensional value

Ratio or interval scaleDifference 0.00 and 0.80 must be 8 time higher than 0.10

Two methods have these pretensionsTime trade-offStandard gamble

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Time Trade-Off

TTO Wheelchair

With a life expectancy: 50 years

How many years would you trade-off for a cure? Max. trade-off is 10 years

QALY(wheel) = QALY(healthy)Y * V(wheel) = Y * V(healthy)50 V(wheel) = 40 * 1

V(wheel) = .8

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Standard Gamble

SG Wheelchair Life expectancy is not important here How much are risk on death are you prepared to

take for a cure? Max. risk is 20% wheels = (100%-20%) life on feetV(Wheels) = 80% or .8

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TWiST: ignores differences in quality of life

TWiSTHealthy = 1Sick (dead) = 0

There is more to life than sick/healthMake intermediate valuesQ-TWiST

• Quality of life adjusted adjusted TWiST

How to scale quality of life?0.0

Quality

of life

1.0

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In health economics: Q-TWiST = QALY

Count life years Value (V) quality of life (Q)

V(Q) = [0..1] • 1 = Healthy• 0 = Dead

One dimension

Adjusted life years (Y) for value quality of life QALY = Y * V(Q)

• Y: numbers of life years• Q: health state• V(Q): the value of health state Q

Also called “utility analysis”

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A new wheelchair for elderly (iBOT) Special post natal care

Which health care program is the most cost-effective?

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A new wheelchair for elderly (iBOT) Increases quality of life = 0.1 10 years benefit Extra costs: $ 3,000 per life year QALY = Y x V(Q) = 10 x 0.1 = 1 QALY Costs are 10 x $3,000 = $30,000 Cost/QALY = 30,000/QALY

Special post natal care Quality of life = 0.8 35 year Costs are $250,000 QALY = 35 x 0.8 = 28 QALY Cost/QALY = 8,929/QALY

Which health care program is the most cost-effective?

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QALY league table

Intervention $ / QALY

GM-CSF in elderly with leukemia 235,958

EPO in dialysis patients 139,623

Lung transplantation 100,957

End stage renal disease management 53,513

Heart transplantation 46,775

Didronel in osteoporosis 32,047

PTA with Stent 17,889

STIP: Short-term inpatient psychotherapy 7,677

Breast cancer screening 5,147

Viagra 5,097

Treatment of congenital anorectal malformations 2,778

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1.0

0.0A B C

Uti

lity

of

Hea

lth

Egalitarian Concerns:Burden of disease

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Implications shifting threshold

QALY are weighted Weighted QALYs are maximized

Health is no longer the only thing maximized

Health status population will drop Differences in health will drop

Egalitarian consideration are incorporated

Burden of disease becomes a criteriaEquity

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CE-ratio by equity

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Conclusion

Cost effectiveness in medicine can be measured Burden of disease is also a criterion

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The YAVIS patient in psychology

YAVISYoung, Attractive, Verbal, Intelligent and Successful

• Young, Attractive, Verbal, Intelligent, and Successful

• Young, Attractive, Verbal, Insightful, and Successful

• Young, Attractive, Vital, Intelligent, and Successful

• Young, Affluent, Verbal, Insured, and Single

Is there a ‘need’ for treatment? Is the QoL low?

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Personality disorder is not YAVIS

00.10.20.30.40.50.60.70.80.9

EQ-5D scores

Personality disorder

Intermittent claudication

Parkinson's disease

Low back pain

Type II diabetes

Schizophrenia outpatients

Hypertension

Asthma

Normal population

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Patient values or values from the general public

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The clinical perspective

Quality of life is subjective…..“Given its inherently subjective nature, consensus was quickly

reached that quality of life ratings should, whenever possible, be elicited directly from patients themselves. “ (Aaronson, in B Spilker (Ed): Quality of life and Pharmacoeconomics in Clinical Trails, 1996, page 180)

The patient values count in clinical quality of life research

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Coping (response shift)

StensmanScan J Rehab Med

1985;17:87-99.

Scores on a visual analogue scale

36 subjects in a wheelchair36 normal matched controls

Mean scoreWheelchair: 8.0Health controls: 8.3

Healthy

Death

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The economic perspective

In a normal market: the consumer values count The patient seems to be the consumer

Thus the values of the patients….

If indeed health care is a normal market… But is it….?

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Health care is not a normal market

Supply induced demands Government control

Financial support (egalitarian structure)

Patient ConsumerThe patient does not pay

Consumer = General publicPotential patients are paying

Health care is an insurance marketA compulsory insurance market

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Health care is an insurance market

Values of benefit in health care have to be judged from a insurance perspective

Who values should be used the insurance perspective?

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Who determines the payments of unemployment insurance?

Civil servantKnowledge: professionalBut suspected for strategical answers

• more money, less problems

• identify with unemployed persons

The unemployed persons themselvesKnowledge: specificBut suspected for strategical answers

General public (politicians)Knowledge: experiencePayers

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Who’s values (of quality of life) should count in the health insurance?

DoctorsKnowledge: professionalBut suspected for strategical answers

• See only selection of patient• Identification with own patient

PatientsKnowledge: disease specificBut suspected for strategical answersBut coping

General publicKnowledge: experiencePayersLike costs: the societal perspective

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The general public should be informed…

Valuing without knowledge makes no senseThyroid Eye Disease

Give description of the disease

A patient with bilateral thyroid eye disease with upper lid retraction and exophthalmos.

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…or use validated questionnaires

MOBILITY I have no problems in walking about I have some problems in walking about I am confined to bed

SELF-CARE I have no problems with self-care I have some problems washing or dressing myself I am unable to wash or dress myself

USUAL ACTIVITIES (e.g. work, study, housework family or leisure activities)

I have no problems with performing my usual activities I have some problems with performing my usual activities I am unable to perform my usual activities

PAIN/DISCOMFORT I have no pain or discomfort I have moderate pain or discomfort I have extreme pain or discomfort

ANXIETY/DEPRESSION I am not anxious or depressed I am moderately anxious or depressed I am extremely anxious or depressed

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Validated Questionnaires in the societal perspective

Describe health states Have values from the general public

Rosser MatrixQWB15DHUI Mark 2HUI Mark 3EuroQol EQ-5D

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Different perspective belong to different research questions

Health economicsSocietal perspective

• General public

Medical decision makingPatients perspective

EpidemiologyDoctors perspective

• Global Burden of Disease