Background: The inevitability of adverse events in medicine arises from human fallibility, negligent care, limits of medical knowledge, risks inherent in medical practice, and biological variability among individuals. A better understanding of the nature and causes of adverse events is necessary to reduce their occurrence and limit their harm. This study describes adverse events identified from a risk-management database that occurred in an out-patient primary care setting.
Methods: Incident reports filed with the risk-management office of an academic medical center between January 1, 1991, and June 30, 1996, by eight primary health care clinics affiliated with the center were eligible for the study. Two independent reviewers assessed the incidents to determine whether there were adverse medical events. Incidents classified as adverse events were analyzed to determine the cause, potential preventability, and outcome.
Results: The prevalence of adverse events was 3.7 per 100,000 clinic visits over a period of 5 1/2 years. Twenty-nine of 35 (83%) adverse events were due to medical errors and were considered preventable. The causes of the adverse events included 9 diagnostic errors (26%), 11 treatment errors (31%), and 9 other errors (26%). Of the adverse events attributed to medical errors, 4 (14%) resulted in a permanent, disabling injury and 1 (3%) resulted in a death.
Conclusions: Serious adverse events appear to occur infrequently in primary care outpatient practice, although these data probably underestimate the overall prevalence. To reduce or prevent the occurrence of adverse events in primary care, better systems for recognizing and tracking them and for assessing their causes are needed.