Variability in Clinical Systems: Applying Modern Quality Control Methods to Health Care

Quality health care depends on timely completion of sequences of clinical care. This study evaluated the concepts and tools of quality management for measuring system performance in ambulatory care. Clinical staff in nine centers of a group model health maintenance organization described the procedure for ordering and completing a complete blood count, mammogram, and surgical consultation. Variability was noted among the processes as intended and as actually performed, as well as inconsistencies reported within and among centers. In two centers investigators tracked performance of key sequences of care and the achievement of other key quality characteristics believed desired by physicians and patients. Computerized patient records and departmental files were the only available sources of data for assessing completion and follow-up of tests and consultations. Even these data were difficult to obtain and, in many instances, incomplete. Although data were often difficult to obtain, the quality management techniques used were helpful in revealing process failures that appeared to be the result of design flaws built into the clinical systems. Robust process designs and improved management information systems for monitoring these processes are recommended to reduce variability and improve the quality of clinical care. Quality management techniques can help reveal process failures that stem from flaws built into clinical systems.