BACKGROUND Diagnostic error can be caused by several types of cognitive bias, which may be reversed by enhancing analytic reasoning.

AIMS To evaluate whether enhancing analytic reasoning can increase diagnostic accuracy in objective structured clinical examination (OSCE) in medical students.

METHODS All fourth-year medical students, randomly assigned to the analytic reasoning or control groups, undertook the OSCE with four cases using standardized patients. The analytic reasoning group was requested to list differential diagnoses and findings compatible or not compatible with each diagnosis prior to providing a diagnosis, while the control group provided a diagnosis without these processes. Mean diagnostic accuracy scores (perfect score, 4.0) from four cases of OSCE were compared between the two groups.

RESULTS One hundred forty-five students were randomly assigned to the analytic reasoning group (n = 65) or the control group (n = 80). The baseline characteristics, including grade point average and the scores from each patient encounter, were comparable between groups. Mean diagnostic accuracy scores were significantly higher in the analytic reasoning group than in the control group (3.40 ± 0.66 versus 3.05 ± 0.98; p = 0.011).

CONCLUSION Enhancement of analytic reasoning may improve diagnostic accuracy in novice doctors.