Quality of care in U.S. hospitals as reflected by standardized measures, 2002-2004.

BACKGROUND In July 2002, the Joint Commission on Accreditation of Healthcare Organizations implemented standardized performance measures that were designed to track the performance of accredited hospitals and encourage improvement in the quality of health care. METHODS We examined hospitals' performance on 18 standardized indicators of the quality of care for acute myocardial infarction, heart failure, and pneumonia. One measure assessed a clinical outcome (death in the hospital after acute myocardial infarction), and the other 17 measures assessed processes of care. Data were collected over a two-year period in more than 3000 accredited hospitals. All participating hospitals received quarterly feedback in the form of comparative reports throughout the study. RESULTS Descriptive analysis revealed a significant improvement (P<0.01) in the performance of U.S. hospitals on 15 of 18 measures, and no measure showed a significant deterioration. The magnitude of improvement ranged from 3 percent to 33 percent during the eight quarters studied. For 16 of the 17 process-of-care measures, hospitals with a low level of performance at baseline had greater improvements over the subsequent two years than hospitals with a high level of performance at baseline. CONCLUSIONS Over a two-year period, we observed consistent improvement in measures reflecting the process of care for acute myocardial infarction, heart failure, and pneumonia. Both quantitative and qualitative research are needed to explore the reasons for these improvements.