OBJECTIVES: The "5-microskills" instructional method for clinical reasoning does not incorporate a step for learners' critical reflection on their predicted hypotheses. This study aimed to correct this shortcoming by inserting a third step in which learners conduct critical self-examinations and furnish evidence that contradicts their predicted hypotheses, resulting in the "6-microskills" method. METHODS: In this cross-sectional study, changes in learners' confidence in their predicted hypotheses were measured and examined to modify confirmation bias and diagnoses. A total of 108 medical students were presented with one randomly assigned clinical vignette from a set of eight, having to: (1) describe their first impression
(2) provide evidence for it
and (3) finally identify inconsistencies/state evidence against it. Participants rated their confidence in their diagnosis at each of the three steps on a 10 point scale, and results were analyzed using a two-way ANOVA with repeated measures for two between-participant levels (correct or incorrect diagnosis) and three within-participant factors (diagnostic steps). The Bonferroni method was used for multiple comparison tests. RESULTS: Mean confidence scores were 5.01 (Step 1), 5.20 (Step 2), and 4.98 (Step 3)
multiple comparisons showed a significant difference between Steps 1-2 (P =.04) and 2-3 (P =.01). Verbalization of evidence in favor of the predicted hypothesis (Step 2) and against it (Step 3) prompted changes in diagnosis in four cases of misdiagnosis (three at Step 2, one at Step 3). CONCLUSIONS: The 6-microskills method, which added a part encouraging learners to verbalize why something "does not fit" with a predicted diagnosis, may effectively correct the confirmation bias associated with diagnostic predictions.