1 Health Economics  Comparing different allocations  Should we spent our money on Wheel chairs Screening for cancer  Comparing costs  Comparing outcome  Outcomes must be comparable  Make a generic outcome measure

2 Outcomes in health economics  Specific outcome are incompatible  Allow only for comparisons within the specific field Clinical successes: successful operation, total cure Clinical failures: “events”  Generic outcome are compatible  Allow for comparisons between fields Life years Quality of life  Most generic outcome  Quality adjusted life year (QALY)

3 Quality Adjusted Life Years (QALY)  Multiply life years with quality index  Quality of life index  1.0 = normal health  0.0 = death (extremely bad health)  Example  Losing sense of sight  Quality of life index is 0.5  Life = 80 years  0.5 x 80 = 40 QALYs

4  A new wheelchair for elderly (iBOT)  Special post natal care Which health care program is the most cost-effective?

5  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?

6 QALY league table

ABC Utility of Health Egalitarian Concerns: Burden of disease

8 CE-ratio by equity

9 Burden as criteria Pronk & Bonsel, Eur J Health Econom 2004, 5:

10 What form of equity?

Citations in PubMed

12 Top 6 journals Cost Utility Analysis

13 Most debate about the QoL estimates  Unidimensional QoL  In QALY we need a unidimensional assessment of Quality of life  Rules out multidimensional questionnaires  SF-36, NHP, WHOQOL

14 Utility assessment  Unidimensional QoL  Often called ‘utility’

15 Who to ask? The patient, of course!

16 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. “ (Niel Aaronson, in B. Spilker: Quality of life and Pharmacoeconomics in Clinical Trails, 1996, page 180)  …therefore ask the patient!

17 Patient values count….  […] the best way to do this, the technology, is a patient-based assessment. They report, they evaluate, they tell you in a highly standardized way, and that information is used with the clinical data and the economic data to get the best value for the health care dollar.”  John Ware

18 A problem in the patient perspective….  Stensman  Scan J Rehab Med 1985;17:  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

19 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….?

20 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

21 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?

22 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

23 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

24 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

25 Validated Questionnaires  Describe health states  Have values from the general public  Rosser Matrix  QWB  15D  HUI Mark 2  HUI Mark 3  EuroQol EQ-5D

26 EQ-5D, HUI and SF-36 Of the shelf instruments….

27 Validated questionnaires

28 The Rosser & Kind Index

29 The Rosser & Kind index  One of the oldest valuation  1978: Magnitude estimation  Magnitude estimation  PTO  N = 70: Doctors, nurses, patients and general public  1982: Transformation to “utilities”  1985: High impact article  Williams A. For Debate... Economics of Coronary Artery Bypass Grafting. British Medical Journal 291: ,  Survey at the celebration of 25 years of health economics: chosen most influential article on health economics

30 More health states  Criticism on the Rosser & Kind index  Sensitivity (only 30 health states)  The unclear meaning of “distress”  The compression of states in the high values  The involvement of medical personnel  New initiatives  Higher sensitivity (more then 30 states)  More and better defined dimensions  Other valuation techniques Standard Gamble, Time Trade-Off  Values of the general public

31 Validated questionnaires

32 No longer value all states  Impossible to value all health states  If one uses more than 30 health states  Estimated the value of the other health states with statistical techniques  Statistically inferred strategies Regression techniques EuroQol, Quality of Well-Being Scale (QWB)  Explicitly decomposed methods Multi Attribute Utility Theory (MAUT) Health Utility Index (HUI)

33 Statistically inferred strategies  Value a sample of states empirically  Extrapolation  Statistical methods, like linear regression  = 1.00  =.70  = ?

34 Explicitly Decomposed Methods  Value dimensions separately  Between the dimensions  What is the relative value of: Mobility…... 20% Mood…….. 15% Self care.… 24%.  Value the levels  Within the dimensions  What is the relative value of Some problems with walking…… 80% Much problems with walking…... 50% Unable to walk…………………….10%

35 Explicitly Decomposed Methods  Combine values of dimensions and levels with specific assumptions  Multi Attribute Utility Theory (MAUT) Mutual utility independence Structural independence

36 Explicitly Decomposed Methods  Health Utilities Index (Mark 2 & 3)  Torrance at McMaster  8 dimensions  Mark 2: health states  Mark 3: health states  The 15-D  Sintonen H.  15 dimensions  3,052,000,000 health states (3 billion)

37 More health states, higher sensitivity ? (1)  EuroQol criticised for low sensitivity  Low number of dimensions Development of EQ-5D plus cognitive dimension  Low number of levels (3) Gab between best and in-between level

38 More health states, higher sensitivity ? (2)  Little published evidence  Sensitivity EQ-5D < SF-36 Compared as profile, not as utility measure  Sensitivity EQ-5D  HUI  Sensitivity  the number of health states  How well maps the classification system the illness?  How valid is the modelling?  How valid is the valuation?

39 More health states, more assumptions  General public values at the most 50 states  The ratios empirical (50) versus extrapolated  Rosser & Kind1:1  EuroQol1:5  QWB1:44  SF-361:180  HUI (Mark III)1:19,400  15D1:610,000,000  What is the critical ratio for a valid validation?

40 SF-36 as utility instrument  Transformed into SF6D  SG  N = 610  Inconsistencies in model  health states  regression technique stressed to the edge  Floor effect in SF6D

41 Conflicting evidence sensitivity SF-36 Liver transplantation, Longworth et al., 2001

42 Conclusions  More states  better sensitivity  The three leading questionnaires  have different strong and weak points

43 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

44 Uni-dimensional value  Like the IQ-test measures intelligence  Ratio or interval scale  Difference 0.00 and 0.80 must be 8 time higher than 0.10  Three popular methods have these pretensions  Visual analog scale  Time trade-off  Standard gamble

45 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

46 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

47 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

48 Consistent picture of difference 103 students

49 Health economics prefer TTO/SG  Visual analogue scale  Easy  No trade-off: no relation to QALY No interval proportions  Standard Gamble / Time trade-Off  Less easy  Trade-off: clear relation to QALY Interval proportions  Little difference between SG and TTO

50 Little difference between Cost/Life Year and Cost/QALY Richard Chapman et al, 2004, Health Economics

51 Difference in QALYs makes little difference in outcome  Richard Chapman et al, 2004  “In a sizable fraction of cost-utility analyses, quality adjusting did not substantially alter the estimated cost-effectiveness of an intervention, suggesting that sensitivity analyses using ad hoc adjustments or 'off-the-shelf' utility weights may be sufficient for many analyses.”  “The collection of preference weight data should […] should only be under-taken if the value of this information is likely to be greater than the cost of obtaining it.”

52 QALYs make a difference when:  Chronic disease  Palliative  Long term negative consequences

53 Conclusions  SG/TTO are preferred in Health economics  Reproducible results  Problems in QALYs are overestimated  Difference in QALYs makes little difference in outcome Compared to cost per life year With exception of chronic illness