Health technology assessment for the NHS in England and Wales.

In healthcare decision making, there is an important functional separation between assessment and appraisal. In the U.K. National Health Service (NHS), this distinction is illustrated by the separation of roles between the Health Technology Assessment Programme and the National Institute for Clinical Excellence. However, it can be seen at every level within the healthcare system. Assessment of a technology is a scientific task that synthesizes all relevant evidence on effectiveness and cost-effectiveness; its results are therefore generalizable. Appraisal of the technology is informed by the assessment but adds context-specific judgments on the applicability of the evidence, the feasibility and impact of alternative options, relative priorities, and wider social and ethical aspects. An explicit distinction between assessment and appraisal is helpful in achieving clarity, consistency, and consensus. It also makes clear the need for a wide range of assessment reviews to support decision making by commissioners, providers, and users of health services. Increasingly, the secondary research supported by the NHS R&D Programme is being distributed electronically. It is also being used to identify areas in which further primary research should be commissioned.