Evidence-Based Medicine: Promises and Problems

1. Evidence-Based Medicine:Promises and Problems Victor R. Fuchs Henry J. Kaiser Jr. Professor Emeritus Stanford University Nuffield Trust, London, 12 May 2003

2. “Evidence-based medicine (EBM) is the integration of best research evidence with clinical expertise and patient values.” David Sackett et al. Evidence-Based Medicine 2nd edition, 2000, p. 1

3. Reasons for Expansion of EBM The Demand for EBM The complexity of modern medicine The high cost of modern medicine The Supply of EBM Innovations that reduce the cost of acquiring, storing, processing, and retrieving information Methodological and substantive advances in mathematics, statistics, and the behavioral sciences that have applications to medical care

4. The Promises of EBM • More effective, safer medical interventions resulting in better health outcomes for patients • Greater uniformity in the quality of care • A slower rate of growth of expenditures for medical care

5. “best research evidence” What does “best” mean? Why only the “best”? Can the best be the enemy of the good? What kind of evidence is excluded by the adjective “research”?

6. “clinical expertise” EBM does not eliminate the need for: Noting signs and symptoms Taking a good history Interpreting results of tests Thinking analytically

7. Physician reasoning “It is neither necessary nor desirable to make every physician a decision analyst, but a reasonable objective would be to give physicians enough experience in quantitative reasoning that they will know how to solve simple problems themselves, when and how to consult an analyst, and how to interpret the advice.” David Eddy, NEJM, 1982

8. “patient values” • Risk aversion • Time preference • Living arrangements • Working arrangements • Medical care vs. other goods and services • Income?

9. “All medical care that is effective should be free to all” A.L. Cochrane, Effectiveness and Efficiency: Random Reflections on Health Services, 1972 Is this possible in 2003?

10. “Although the average beliefs in a community are appropriate for deciding, for example, whether chemotherapy or surgery should be paid for with public funds, decisions for individual patients must reflect their own personal beliefs and preferences.” Sackett, et al., EBM, 2nd ed., p. 180

11. EBM and Expenditures on Medical Care Will EBM act as a brake on expenditures? Yes. It will reduce utilization of ineffective care. Yes. It will show that some relatively inexpensive interventions are as effective as more costly alternatives. No. It will show that some interventions are more effective than any alternative, albeit at great cost relative to their benefit. For EBM to realize its potential, it is necessary to integrate it with cost-benefit analysis.

12. Summary • EBM is a great advance over informal, non-quantitative approaches to clinical decisions. • The complexity and high cost of modern medicine make EBM necessary. Innovations outside of medicine make it feasible. • EBM should result in more effective, more uniform, and more efficient medical care. • EBM is an adjunct, not a substitute for physicians who can diagnose accurately, access evidence efficiently, and think analytically. • The integration of EBM with cost-benefit analysis poses a major challenge for health policy.