Classification of medical errors and preventable adverse events in primary care: A synthesis of the literature

OBJECTIVE: To describe and classify process errors and preventable adverse events that occur from medical care in outpatient primary care settings. STUDY DESIGN: Systematic review and synthesis of the medical literature. DATA SOURCES: We searched MEDLINE and the Cochrane Library from 1965 through March 2001 with the MESH term medical errors, modified by adding family practice, primary health care, physicians/family, or ambulatory care and limited the search to English-language publications. Published bibliographies and Web sites from patient safety and primary care organizations were also reviewed for unpublished reports, presentations, and leads to other sites, journals, or investigators with relevant work. Additional papers were identified from the references of the papers reviewed and from seminal papers in the field. OUTCOMES MEASURED: Process errors and preventable adverse events. RESULTS: Four original research studies directly studied and described medical errors and adverse events in primary care, and 3 other studies peripherally addressed primary care medical errors. A variety of quantitative and qualitative methods were used in the studies. Extraction of results from the studies led to a classification of 3 main categories of preventable adverse events: diagnosis, treatment, and preventive services. Process errors were classified into 4 categories: clinician, communication, administration, and blunt end. CONCLUSIONS: Original research on medical errors in the primary care setting consists of a limited number of small studies that offer a rich description of medical errors and preventable adverse events primarily from the physician's viewpoint. We describe a classification derived from these studies that is based on the actual practice of primary care and provides a starting point for future epidemiologic and interventional research. Missing are studies that have patient, consumer, or other health care provider input.