Teaching heuristics and mnemonics to improve generation of differential diagnoses

Background: Differential diagnosis (DDx) is one of the key cognitive skills that medical learners must develop. However, little is known regarding the best methods for teaching DDx skills. As metacognition plays a fundamental role in the diagnostic process, we hypothesized that the teaching of specific heuristics and mnemonics collectively termed metamemory techniques (MMTs) would enhance the capacity of medical students to generate differential diagnoses. Methods: In a 90-min DDx workshop, third-year medical students (N = 114) were asked to generate differentials before and after learning each of four MMTs. Differential sizes were compared using a linear mixed-effect model. Students also completed a post-session questionnaire which included a subjective ranking of the MMTs, as well as Likert-scale and free-text sections for course feedback. Results: One MMT (the Mental CT Scan, an anatomic visualization technique) significantly increased the size of student differentials (+13.3%, p =.0005). However, a marked cumulative increase across all four MMTs was noted (+36.5%, p <.0001). A majority of students ranked the Mental CT Scan the most useful MMT (51.5%). They found the workshop both worthwhile (4.51/5, CI 4.33–4.69) and enjoyable (4.33/5, CI 4.12–4.55), and considered the MMTs they learned useful and practical (4.49/5, CI 4.32–4.67). Conclusion: The MMT-based DDx workshop was effective in enhancing the skill of DDx generation, and was rated very favorably by students.