RESUMO
CONTEXT: Diagnostic competence in students is a major medical education goal. Adding instructional guidelines to prompt deliberate reflection fosters medical students' diagnostic proficiency. This study investigates the effects of this teaching strategy on diagnostic accuracy in solving clinical cases of different complexity levels by novice and senior students. METHOD: Eighty third-year and 62 sixth-year medical students participated in this three-phase experimental study. First, participants were randomly assigned to one of three experimental conditions (free reflection, cued reflection and worked example) to diagnose 12 clinical text-based cases, following different levels of deliberate reflection. In an immediate test and a delayed test, the participants diagnosed varied sets of 12 cases, six involving the same diseases (four routine and two rare). The main outcomes were the diagnostic accuracy scores achieved for the cases assessed by repeated measures of analysis of variance for each category. RESULTS: There was a signiï¬cant primary effect of experimental condition (P < .001), year of training (P < .001) and study phase (P < .001) on the diagnostic accuracy achieved. The use of deliberate reflection in addition to instructional guidelines resulted in improved results in the immediate test for all cases evaluated (P < .001), regardless of participants' seniority. In the delayed test, this benefit was maintained for simple cases (P < .001). For complex cases, the benefit was maintained only for senior students (P < .001). The cued reflection and worked example groups did not differ in performance (P > .05), but both groups surpassed the free reflection group (P < .001), regardless of the students' learning stage and case complexity.