Missed diagnosis of cancer in primary care: Insights from malpractice claims data.

BACKGROUND: In the ambulatory setting, missed cancer diagnoses are leading contributors to patient harm and malpractice risk; however, there are limited data on the malpractice case characteristics for these cases. OBJECTIVE: The aim of this study was to examine key features and factors identified in missed cancer diagnosis malpractice claims filed related to primary care and evaluate predictors of clinical and claim outcomes. METHODS: We analyzed 2155 diagnostic error closed malpractice claims in outpatient general medicine. We created multivariate models to determine factors that predicted case outcomes. RESULTS: Missed cancer diagnoses represented 980 (46%) cases of primary care diagnostic errors, most commonly from lung, colorectal, prostate, or breast cancer. The majority (76%) involved errors in clinical judgment, such as a failure or delay in ordering a diagnostic test (51%) or failure or delay in obtaining a consult or referral (37%). These factors were independently associated with higher-severity patient harm. The majority of these errors were of high severity (85%). CONCLUSIONS: Malpractice claims involving missed diagnoses of cancer in primary care most often involve routine screening examinations or delays in testing or referral. Our findings suggest that more reliable closed-loop systems for diagnostic testing and referrals are crucial for preventing diagnostic errors in the ambulatory setting.