Abstract
The idea that physicians should accept recommendations from learned colleagues on how to practice medicine is probably as old as medicine itself, but beginning around 1990, it took on new urgency in the face of rising health care costs, widespread, unjustifiable variation in practice patterns, concerns about medical errors and quality of care, and what some perceived to be perverse effects of the malpractice system. One solution put forward was practice guidelines, which the Institute of Medicine defined as systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances.