This background paper traces the development within American health care of two interrelated trends and activities: an evidence-based approach to medical practice and the critical evaluation of new technologies with respect to their costs and effectiveness. Over the past 35 years each of these developments has increasingly shaped the coverage decisions of public and private health insurers, and their importance for coverage policy is certain to grow. The paper also contrasts the different approaches to such “evidence-” or “value-based” coverage policy in the mixed public and private U.S. health care enterprise with the approach taken in Great Britain’s single-payer National Health Service
