Evidence-Based Medicine:Promises and Problems

Victor R. FuchsHenry J. Kaiser Jr. Professor Emeritus

Stanford University

Nuffield Trust, London, 12 May 2003

“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

Reasons for Expansion of EBMThe Demand for EBM

The complexity of modern medicineThe high cost of modern medicine

The Supply of EBMInnovations 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

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

“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”?

“clinical expertise”

EBM does not eliminate the need for:

Noting signs and symptoms

Taking a good history

Interpreting results of tests

Thinking analytically

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

“patient values”

• Risk aversion

• Time preference

• Living arrangements

• Working arrangements

• Medical care vs. other goods and services

• Income?

“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?

“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

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.

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.