Abstract
BACKGROUND: Physicians may receive diagnostic information in different orders, and there is a lack of empirical evidence that the order of presentation may influence clinical reasoning. OBJECTIVE: We investigated whether diagnostic accuracy of chest pain cases is influenced by the order of presentation of the history and electrocardiogram (EKG) to cardiology residents. METHODS: We conducted an experimental study during a resident training in 2019. Twelve clinical cases were presented in 2 diagnostic rounds. Residents were randomly allocated to seeing the EKG first (EKGF) or the history first (HF). The mean diagnostic accuracy scores (range 0-1) and confidence level (0-100) in each diagnostic round and time needed to make the diagnosis were evaluated. RESULTS: The final diagnostic accuracy was higher than the initial in both groups. After the first round, diagnostic accuracy was higher in HF (n=24) than in EKGF (n=28). Time taken to judge the history was comparable in both groups. Time taken to judge the EKG was shorter in HF (40±11 vs 64±13 seconds; P<.01). Time invested in the second round was significantly correlated with changing the initial diagnosis. A significant difference was observed in confidence ratings after the initial diagnosis, with EKGF reporting less confidence relative to HF. CONCLUSIONS: The order in which history and EKG are presented influences the clinical reasoning process.