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.