Electronic health record-based surveillance of diagnostic errors in primary care

Background: Diagnostic errors in primary care are harmful but difficult to detect. The authors tested an electronic health record (EHR)-based method to detect diagnostic errors in routine primary care practice. Methods: The authors conducted a retrospective study of primary care visit records 'triggered' through electronic queries for possible evidence of diagnostic errors: Trigger 1: A primary care index visit followed by unplanned hospitalisation within 14 days and Trigger 2: A primary care index visit followed by >= 1 unscheduled visit(s) within 14 days. Control visits met neither criterion. Electronic trigger queries were applied to EHR repositories at two large healthcare systems between 1 October 2006 and 30 September 2007. Blinded physician-reviewers independently determined presence or absence of diagnostic errors in selected triggered and control visits. An error was defined as a missed opportunity to make or pursue the correct diagnosis when adequate data were available at the index visit. Disagreements were resolved by an independent third reviewer. Results: Queries were applied to 212 165 visits. On record review, the authors found diagnostic errors in 141 of 674 Trigger 1-positive records (positive predictive value (PPV)=20.9%, 95% CI 17.9% to 24.0%) and 36 of 669 Trigger 2-positive records (PPV=5.4%, 95% CI 3.7% to 7.1%). The control PPV of 2.1% (95% CI 0.1% to 3.3%) was significantly lower than that of both triggers (p <= 0.002). Inter-reviewer reliability was modest, though higher than in comparable previous studies (K=0.37 (95% CI 0.31 to 0.44)). Conclusions: While physician agreement on diagnostic error remains low, an EHR-facilitated surveillance methodology could be useful for gaining insight into the origin of these errors.