1. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 1 by Donald S. Shepard, Ph.D. Schneider Institute for Health Policy Heller School, MS 035 Brandeis University Waltham, MA 02454-9110 USA Tel: 781-736-3975 Fax: 781-736-3965 Web: http://www.sihp.brandeis.edu/shepard E-mail: Shepard@Brandeis.edu Monday, Sept. 17 Measuring effectiveness and other CEA considerations

2. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 2 Practical information Teaching assistant: Jsuaya@Brandeis.edu Administrative assistant: Linda Purrini, Next to library in Heller 781-736-3930 Purrini@Brandeis.edu Cost of packet: $6.00

3. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 3 Donald S. Shepard, Ph.D. Schneider Institute for Health Policy Heller School, MS 035 Brandeis University Waltham, MA 02454-9110 USA Tel: 781-736-3975 Fax: 781-736-3965 Web: http://www.sihp.brandeis.edu/shepard E-mail: Shepard@Brandeis.edu Measuring Effectiveness and Outcomes, QALYs and DALYs

4. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 4 Outline Types of indexes Measuring national disease burden Health status questionnaires

5. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 5 Needs for combining length and quality of life Assessing the disease burden of a country or a region, to see which health problems are greatest, and how one country or region compares with another. Evaluating a program that may impact both mortality and morbidity.

6. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 6 Indexes for combining length and quality of life Quality Adjusted Life Years, QALYs (Zeckhauser and Shepard, 1976) Potential Days of Life Lost, PDLLs (Ghana health assessment team, 1980) Disability Adjusted Life Years, DALYs (World Development Report, 1993)

7. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 7 Types of scales for assessing quality of life Value scale: a measure of preferences on a scale with arbitrary endpoints (example, SF36, scale of 0 to 100). Utility scale: a measure of preferences on a scale with endpoints of 0 and 1 and spacing consistent with probability theory.

8. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 8 Burden of disease

9. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 9 Ways of assessing utilities Probability approach – breakeven probability Time tradeoff - breakeven time

10. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 10 General health question In general, would you say your health is poor, fair, good, very good, or excellent? 1  poor 2  fair 3  good 4  very good 5  excellent

11. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 11 Limitation of physical activities Here are a list of activities that you might do during a typical day. How much does your health limit you right now in moderate activities, such as moving a table, pushing a vacuum cleaner, bowling, or playing golf? 1  A lot 2  A little 3  Not at all

12. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 12 Limitation of social activities During the past 4 weeks, how much of the time has your physical health or emotional problems interfered with your social activities like visiting with friends or relatives? 1  All of the time 2  Most of the time 3  A good bit of the time 4  Some of the time 5  A little of the time 6  None of the time

13. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 13 Time tradeoff Time tradeoff - find the breakeven time Suppose we were to live 10 years with an impaired state, I Instead, we could live Y years with perfect health. Suppose the the value y would make us just indifferent. Then the utility of I is y / 10. E.g., if y is 7, then the utility is 7/10 = 0.70

14. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 14 Von Neumann – Morgenstern Utility 1 Suppose we have a “good” outcome which has a utility of 1 (e.g. living year in perfect health) Bad outcome has a utility of 0 (e.g. dying at the start of the year) Intermediate outcome (I) has utility of x (e.g. living with a health limitation), x = u(I)

15. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 15 Von Neumann – Morgenstern Utility 2 Suppose I is indifferent between probability p of good outcome, and 1-p of bad outcome The utility is von Neumann-Morgernstern if x equals p.

16. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 16 Illustration: gastroenteritis in Ghana, c. 1980

17. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 17 Remaining life expectancy by age, Ghana (1968)

18. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 18 Disease burden for gastroenteritis (1): Mortality loss burden per death Days lost per death = Remaining life expectancy (years) at age of death 52.8 x Days per year365.25 = Days lost per death19,285

19. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 19 Disease burden for gastroenteritis (2): Mortality loss burden per case Days lost per case from mortality = Case fatality rate0.01 x Days lost per death19,285 = Days lost per fatal case192.85

20. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 20 Disease burden for gastroenteritis (3): Morbidity loss burden per case Days lost per non-fatal case = Average duration per surviving case (days) 14 x Proportion surviving0.99 = Days lost per non-fatal case13.86

21. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 21 Disease burden for gastroenteritis (4): Total burden per case (days) Total days lost per case = Days lost per fatal case192.85 + Days lost per non-fatal case13.86 = Days lost per case206.71 Note: Mortality share (% from fatal cases)93%

22. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 22 Disease burden for gastroenteritis (5): Total annual burden per 1000 persons Total annual burden per 1000 persons = Total burden per case206.71 x Number of new cases per year (incidence) 70 = Total annual burden per 1000 persons 14,470

23. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 23 Extensions: Discounting of health impacts Impacts in future years should be discounted, just as money is discounted Discounting arises due to “time preference”: –We are anxious to get good things soon. –If we have to wait, them “good” is less highly valued now.

24. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 24 Discount factors

25. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 25 Graph of discount factors (at 3%)

26. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 26 Table of DALYs

27. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 27 DALYs from a life of specified number of years

28. Schneider Institute for Health Policy Heller Graduate School Brandeis University September 2001 28 Disease burden exercise Illustrate the calculation of PDLLs from exercise on web site http://www.sihp.brandeis.edu/shepard