Until recently, we relied primarily on professional judgment to ensure that patients received high-quality medical care. Hospitals routinely monitored poor outcomes, such as deaths or infections, to identify ways to improve the quality of care. In rare cases, medical societies reviewed the performance of physicians. However, monitoring of and improvement in quality were generally left to individual clinicians.
This situation has changed dramatically. We have learned that practice patterns and the quality of medical care vary much more than many people had realized, our ability to measure the quality of care has advanced considerably, and clinicians are increasingly interested in having objective information about their practices. Furthermore, patients and purchasers want to know more about the quality of care available to them.