CONSISTENCY IN PERFORMANCE AMONG PRIMARY-CARE PRACTITIONERS

OBJECTIVES. The authors studied the consistency of performance of indi vidual physicians to evaluate the identification of outlier practition ers as a strategy for improving patient care. METHODS. The authors use d a data base containing information on 430 practitioners caring for 6 ,090 patients in 16 group practices. The authors analyzed inter- and i ntraphysician differences in performance on the basis of review criter ia for 8 patient care guidelines. These criteria allowed for a variety of acceptable clinical strategies, incorporated decision tree logic, and included input from participating practitioners. The authors took steps to maximize validity and controlled for potentially confounding characteristics of patients and practitioners. The authors identified outliers, evaluated the significance of differences between outliers a nd nonoutliers, and studied variations in performance across cases and guidelines in conformance with guidelines. RESULTS. The authors ident ified a few statistically significant outliers. Correlations for perfo rmance across cases seen by a given physician were low. The highest po sitive correlation for performance between any pair of guidelines was 0.32. CONCLUSIONS. The performance of a given practitioner is highly v ariable from patient to patient and from guideline to guideline. Thus, strategies focusing solely on substandard outliers will miss opportun ities to improve performance.