Deborah DiNardo, Sarah Tilstra, Melissa McNeil, William Follansbee, Shanta Zimmer, Coreen Farris, Amber E. Barnato
February 9, 2018
Background: While there is some experimental evidence to support the use of cognitive forcing strategies to reduce diagnostic error in residents, the potential usability of such strategies in the clinical setting has not been explored. We sought to test the effect of a clinical reasoning tool on diagnostic accuracy and to obtain feedback on its usability and acceptability. Methods: We conducted a randomized behavioral experiment testing the effect of this tool on diagnostic accuracy on written cases among post-graduate 3 (PGY-3) residents at a single internal medical residency program in 2014. Residents completed written clinical cases in a proctored setting with and without prompts to use the tool. The tool encouraged reflection on concordant and discordant aspects of each case. We used random effects regression to assess the effect of the tool on diagnostic accuracy of the independent case sets, controlling for case complexity. We then conducted audiotaped structured focus group debriefing sessions and reviewed the tapes for facilitators and barriers to use of the tool. Results: Of 51 eligible PGY-3 residents, 34 (67%) participated in the study. The average diagnostic accuracy increased from 52% to 60% with the tool, a difference that just met the test for statistical significance in adjusted analyses (p=0.05). Residents reported that the tool was generally acceptable and understandable but did not recognize its utility for use with simple cases, suggesting the presence of overconfidence bias. Conclusions: A clinical reasoning tool improved residents’ diagnostic accuracy on written cases. Overconfidence bias is a potential barrier to its use in the clinical setting.