Background: The epidemiology, risks, and outcomes of errors in primary care are poorly understood. Malpractice claims brought for negligent adverse events offer a useful insight into errors in primary care.
Methods: Physician Insurers Association of America malpractice claims data (1985–2000) were analyzed for proportions of negligent claims by primary care specialty, setting, severity, health condition, and attributed cause. We also calculated risks of a claim for condition-specific negligent events relative to the prevalence of those conditions in primary care.
Results: Of 49 345 primary care claims, 26 126 (53%) were peer reviewed and 5921 (23%) were assessed as negligent; 68% of claims were for negligent events in outpatient settings. No single condition accounted for more than 5% of all negligent claims, but the underlying causes were more clustered with "diagnosis error" making up one third of claims. The ratios of condition-specific negligent event claims relative to the frequency of those conditions in primary care revealed a significantly disproportionate risk for a number of conditions (for example, appendicitis was 25 times more likely to generate a claim for negligence than breast cancer).
Conclusions: Claims data identify conditions and processes where primary health care in the United States is prone to go awry. The burden of severe outcomes and death from malpractice claims made against primary care physicians was greater in primary care outpatient settings than in hospitals. Although these data enhance information about error related negligent events in primary care, particularly when combined with other primary care data, there are many operating limitations.