Medical Education 2012: 46: 464–472
Objectives Developing diagnostic competence in students is a major goal of medical education, but there is little empirical evidence on instructional strategies that foster the acquisition of this competence. The aim of this study was to investigate the effects of structured reflection compared with the generation of immediate or differential diagnosis while practising with clinical cases on learning clinical diagnosis.
Methods This was a three-phase experimental study. During a learning phase, 46 Year 4 students diagnosed six clinical cases under different experimental conditions: structured reflection, immediate diagnosis, or differential diagnosis. This was followed by an immediate test and a delayed test administered 1 week later. Each test consisted of diagnosing four different cases of diseases presented in the learning phase. Performance in diagnosing these new cases was used as a measure of learning.
Results Repeated-measures analysis of variance on the mean diagnostic accuracy scores (range: 0–1) showed a significant interaction between performance moment (i.e. performance in the learning phase and on each test) and instructions followed during the learning phase (p = 0.003). Follow-up analyses of this interaction showed that diagnostic performance did not differ between conditions in the learning phase. On the immediate test, scores in the reflection condition (mean = 0.48, 95% confidence interval [CI] 0.38–0.58) were significantly lower than scores in the differential diagnosis condition (mean = 0.62, 95% CI 0.54–0.70; p = 0.012) and marginally lower than those in the immediate diagnosis condition (mean = 0.61, 95% CI 0.52–0.70; p = 0.04). One week later, however, scores in the reflection condition (mean = 0.66, 95% CI 0.56–0.76) significantly outperformed those in the other conditions (differential diagnosis: mean = 0.48, 95% CI 0.37–0.58 [p < 0.01]; immediate diagnosis: mean = 0.52, 95% CI 0.43–0.60 [p = 0.01]). Comparisons within experimental conditions showed that performance from the immediate to the delayed test decreased in the immediate and differential diagnosis conditions (immediate diagnosis: p = 0.042; differential diagnosis: p = 0.012), but increased in the reflection condition (p = 0.003).
Conclusions Structured reflection while practising with cases appears to foster the learning of clinical knowledge more effectively than the generation of immediate or differential diagnoses and therefore seems to be an effective instructional approach to developing diagnostic competence in students.