The Welsh Institute for Minimal Access Therapy colonoscopy suitcase has construct and concurrent validity for colonoscopic polypectomy skills training: a prospective, cross-sectional study

Background The Welsh Institute for Minimal Access Therapy (WIMAT) colonoscopy suitcase is an ex vivo porcine simulator for polypectomy training. Objective To establish whether this model has construct and concurrent validity. Design Prospective, cross-sectional study. Setting Endoscopic training center. Participants Twenty novice (N), 20 intermediate (I), 20 advanced (Ad), and 20 expert (E) colonoscopists. Intervention A simulated polypectomy task aimed at removing 2 polyps; A (simple), B (complex). Main Outcome Measurements Two accredited colonoscopists, blinded to group allocation, scored performances according to Direct Observation of Polypectomy Skills (DOPyS) assessment parameters. Group performances were compared. Real-life DOPyS scores were correlated to simulator DOPyS results. Results Median overall DOPyS scores for novices were 1.00 (1.00-1.87) for A and 0.50 (0.00-1.00) for B (A vs B; P < .01). Intermediates scored 2.50 (2.00-2.88) for A and 2.00 (1.13-2.50) for B (A vs B; P = .03). The advanced group scored 3.00 (2.50-3.50) for A and 2.50 (2.00-3.00) for B (A vs B; P = .01). Experts scored 3.00 (3.00-3.88) for A and 3.00 (2.50-3.50) for B (A vs B; P = .47). Intergroup comparisons for A were, N vs I; P < .01, N vs Ad; P < .01, N vs E; P < .01, I vs Ad; P < .01, I vs E; P < .01, and Ad vs E; P = .46. Intergroup comparisons for B were, N vs I; P < .01, N vs Ad; P < .01, N vs E; P < .01, I vs Ad; P = .03, I vs E; P <.01, and Ad vs E; P = .06. There was no difference between real-life DOPyS scores and simulator scores (0.07). Limitations The model does not have inbuilt assessment parameters. Conclusion This simulator demonstrates construct and concurrent validity for colon polypectomy training