Presentation patterns for initial incorrect diagnosis in diagnostic errors

OBJECTIVES: The typicality of clinical presentations for the initial (incorrect) diagnosis in cases of diagnostic error remains poorly understood. We conducted this study to systematically characterize these clinical presentation patterns in diagnostic-error cases using the PSUC classification. METHODS: We retrospectively applied the PSUC classification (Primary, Suggestive, Uncommon, Chameleon features) to the initial diagnoses of cases from a dataset of diagnostic-error case reports. Cases with a single explicitly named initial working diagnosis were included. Classification was performed by 20 reviewers using calibrated, pair-based consensus. We summarized the distribution of initial-diagnosis PSUC patterns and the commonality of the initial and final diagnoses. RESULTS: We included 306 cases in this study. In most error cases, the presentation carried the Primary features of the initial (incorrect) diagnosis (258 cases, 84.3 %); however, only 14.1 % were purely typical (Primary features alone present), and 64.0 % of cases with Primary features also carried at least one Uncommon or Chameleon feature. Secondarily, the proportion of common diseases decreased from 52.9 % at the initial diagnosis to 16.1 % at the final diagnosis, and the most frequent commonality transition was from a common initial diagnosis to an uncommon final diagnosis (43.0 %). CONCLUSIONS: Most diagnostic errors in this dataset occurred in cases that carried Primary features of the wrong diagnosis, suggesting that the superficial resemblance to the wrong diagnosis largely drives them. Because disconfirmatory features coexisted with Primary features in most cases, diagnostic-safety strategies may benefit from directing attention to these discriminating features even when the initial diagnosis appears superficially typical.