Developing evidence-based clinical practice guidelines: lessons learned by the US Preventive Services Task Force.

The US Preventive Services Task Force is an expert panel established by the federal government in 1984 to develop evidence-based practice guidelines on screening tests and other preventive services. Its recommendations are published elsewhere. This article explores the lessons learned in the process of developing and disseminating the recommendations. Topics include project organization (analytic philosophy, project sponsorship, panel composition, topic selection); the review of evidence (selecting outcome measures for judging effectiveness, constructing "causal pathways," searching the literature, rating the evidence, synthesizing the results); crafting recommendations (extrapolation, assessing magnitude, balancing risks and benefits, addressing costs, dealing with insufficient data, separating science from policy); peer review; collaboration with other groups; evaluating impact on clinicians' knowledge, attitudes, and behavior; updating recommendations; and defining a research agenda. The lessons learned suggest potential refinements in the future work of the task force and other groups engaged in guideline development.