Cost-Effectiveness in Medicine An Interactive Introduction

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Cost-Effectiveness in MedicineAn Interactive
Introduction

• Jan J. v. Busschbach, Ph.D.
• Erasmus MC
• Institute for Medical Psychology and
  Psychotherapy
• Viersprong 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

• TWiST
• Developed by Richard Gelber (statistician)
• In search for a typical cancer problem
• Often prolonged life but also a reductions in
  quality of life
• At the beginning (side effects)
• At the end
• Only count the days without symptoms of disease
  and subjective toxic effects of the treatment

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TWiST in cancer therapy
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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

• TWiST
• Healthy 1
• Sick (dead) 0
• There is more to life than sick/health
• Make intermediate values
• Q-TWiST
• Quality of life adjusted adjusted TWiST
• How to scale quality of life?

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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 individuals 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 definitions
• Researchers 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 research
• Clinical 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
• Questionnaires
• Standardize questions and response
• Reproducible results sciences
• Quantify subjectivity
• Operational defined
• Like IQ and temperature.

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

• Choose items
• Are you able to walk one kilometer ?
• Do you feel depressed ?
• Choose response mode
• Binary yes / no
• Multiple (Likert) yes / at bid / hardly / no
• Continuous (Visual Analogue Scale) Always
  X Never
• Combine items to dimensions of quality of life
• Sum up the items belonging to one dimension
• Rescale 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 emotional
• On 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

• Wheelchair
• Some problems in walking about
• Some problems washing or dressing
• Some problems with performing usual activities
• Some pain or discomfort
• No psychosocial problems

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Visual Analogue Scale

• VAS
• Also 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 versusworse imaginable
  health

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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

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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 scale
• Difference 0.00 and 0.80 must be 8 time higher
  than 0.10
• Two methods have these pretensions
• Time trade-off
• Standard 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 feet
• V(Wheels) 80 or .8

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TWiST ignores differences in quality of life

• TWiST
• Healthy 1
• Sick (dead) 0
• There is more to life than sick/health
• Make intermediate values
• Q-TWiST
• Quality of life adjusted adjusted TWiST
• How to scale quality of life?

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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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Which health care program is the most
cost-effective?

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

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Which health care program is the most
cost-effective?

• 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

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QALY league table
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Egalitarian ConcernsBurden of disease
1.0
Utility of Health
0.0
A
B
C
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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 criteria
• Equity

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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

• YAVIS
• Young, 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
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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)

• Stensman
• Scan J Rehab Med 19851787-99.
• Scores on a visual analogue scale
• 36 subjects in a wheelchair
• 36 normal matched controls
• Mean score
• Wheelchair 8.0
• Health controls 8.3

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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 ? Consumer
• The patient does not pay
• Consumer General public
• Potential patients are paying
• Health care is an insurance market
• A 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 servant
• Knowledge professional
• But suspected for strategical answers
• more money, less problems
• identify with unemployed persons
• The unemployed persons themselves
• Knowledge specific
• But suspected for strategical answers
• General public (politicians)
• Knowledge experience
• Payers

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Whos values (of quality of life) should count in
the health insurance?

• Doctors
• Knowledge professional
• But suspected for strategical answers
• See only selection of patient
• Identification with own patient
• Patients
• Knowledge disease specific
• But suspected for strategical answers
• But coping
• General public
• Knowledge experience
• Payers
• Like costs the societal perspective

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The general public should be informed

• Valuing without knowledge makes no sense
• Thyroid 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

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Validated Questionnaires in the societal
perspective

• Describe health states
• Have values from the general public
• Rosser Matrix
• QWB
• 15D
• HUI Mark 2
• HUI Mark 3
• EuroQol EQ-5D

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Different perspective belong to different
research questions

• Health economics
• Societal perspective
• General public
• Medical decision making
• Patients perspective
• Epidemiology
• Doctors perspective
• Global Burden of Disease