Quality improvement among primary care practitioners: an overall appraisal of results of the Ambulatory Care Medical Audit Demonstration Project.

OBJECTIVES The authors appraised the overall conclusions of a randomized, controlled trial of quality assurance in 16 primary care group practices, addressing the relevance of findings to health maintenance organizations in the 1990s. METHODS The framework was the analogy of opening the "black box" of quality assurance interventions to examine circumstances in which interventions worked. RESULTS External pressures for quality improvement were weak during the study and knowledge of continuous quality improvement principles lacking. Correspondingly, within study practices, pre-existing mechanisms lacked the rigorous data-driven approach and system focus of the quality assurance cycles conducted. Additional barriers to demonstrating an effect of quality assurance included pre-existing good performance, high variability in performance measurements, and lack of time within the study for radical re-design of systems. Improvement in performance for one guideline was impeded by change of practice recommendations during the study. Nevertheless, clinically and statistically significant improvements in quality were obtained in five of the seven remaining guidelines, with effects peaking after feedback of performance results. A sixth guideline showed improvement in practices in which the physician leader influenced colleagues to improve. The seventh guideline showed improvement that did not reach statistical significance, in part because of lack of statistical power. CONCLUSIONS This study demonstrated the effectiveness of cycles of quality measurement and improvement. The findings provide guidance for health-care practitioners and managers of the 1990s, for whom quality measurement and improvement has become a priority.