Are clinical practice guidelines a means for improving the quality of health care? For saving money in the health care system? For solving the malpractice problem? For making the health care system work better for all? Or, are they a recipe for disaster? This overview sets out conceptual, definitional, and practical aspects of clinical practice guidelines as a broad framework for reflecting on the issue of what guidelines are and why they count. It draws mainly on work done since 1990 (...) at the Institute of Medicine and focuses on five questions. First, what are guidelines, and who develops them? Second, what criteria or principles should be used to create good guidelines? Third, what problems or pitfalls exist in developing and disseminating guidelines? Fourth, in what ways can guidelines help improve medical care, and in what ways will they not be as practical or useful, particularly with respect to quality of care? Finally, what ethical context might guide deliberations on this topic? (shrink)