Measuring clinical performance of individual internists in office and hospital practice.

No standardized methods exist for reliably measuring physicians' performance against clinically valid standards. In this study, statistically reliable peer review based on current national standards of internal medicine was used to evaluate the clinical performance of 66 internists in office and hospital practice. Evaluation was limited to the substantiation of diagnosis, prescribing indicated drug regimen, monitoring, and attaining expected patient response. Performance in substantiating diagnosis was better than in therapeutic management, and management in hospitalized patients was superior to office management. Superior performance by a physician was not consistent across diagnoses, but substandard office treatment in at least one diagnosis was associated with substandard office treatment in other conditions. Internists' performance was unrelated to their certification status but inversely related to the number of years since graduation from medical school. This method could be used to evaluate the effectiveness of continuing education in improving physicians' performance and to validate current examinations used in recertifying internists.