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1 Cost-Effectiveness in Medicine An 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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2 New cancer therapy SymptomsDrug XDrug Y Survival days 300 400 Days sick of chemotherapy 10 150 Days sick of disease 100 30 TWiST 190 220
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3 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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4 TWiST in cancer therapy
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5 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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6 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? 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 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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13 SF-36
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14 SF-36
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15 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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16 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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17 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 versus worse imaginable health Dead Normal health X
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18 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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19 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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20 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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21 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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22 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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23 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? 0.0 Quality of life 1.0
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24 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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25 A new wheelchair for elderly (iBOT) Special post natal care Which health care program is the most cost-effective?
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26 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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27 QALY league table
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28 1.0 0.0 ABC Utility of Health Egalitarian Concerns: Burden of disease
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29 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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30 CE-ratio by equity
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31 Conclusion Cost effectiveness in medicine can be measured Burden of disease is also a criterion
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32 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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33 Personality disorder is not YAVIS
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34 Patient values or values from the general public
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35 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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36 Coping (response shift) Stensman Scan J Rehab Med 1985;17:87-99. Scores on a visual analogue scale 36 subjects in a wheelchair 36 normal matched controls Mean score Wheelchair: 8.0 Health controls: 8.3 Healthy Death
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37 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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38 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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39 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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40 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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41 Who’s 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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42 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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43 …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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44 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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45 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
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