1. 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

2. 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

3. 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

4. 4 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

5. 5 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

6. 6 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

7. 7 Time Trade-Off  QALY: Quality Adjusted Life Years  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) =.80

8. 8 EuroQol EQ-5D: of the shelf QALY value  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

9. 9 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”

10. 10  A new wheelchair for elderly (iBOT)  Special post natal care Which health care program is the most cost-effective?

11. 11  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?

12. 12 QALY league table

13. 13 1.0 0.0 ABC Utility of Health Egalitarian Concerns: Burden of disease

14. 14 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

15. 15 CE-ratio by equity

16. 16 Conclusion  Cost effectiveness in medicine can be measured  Burden of disease is also a criterion