A Prospective Tandem Colonoscopy Study to Determine Proximal Colon Polyp Miss Rate Among Gastroenterology Trainees

BACKGROUND: Existing colonoscopy quality metrics have limited utility for trainees. In particular, the adenoma detection rate may reflect trainer rather than trainee competence. Polyp miss rates may be more objective and feasible metrics of trainee colonoscopy quality. The aim of this study was to assess the proximal colon adenoma miss rate (AMR) and sessile serrated polyp miss rate (SMR) among gastroenterology trainees using a tandem colonoscopy study design. METHODS: We prospectively recruited adult patients scheduled for screening or surveillance colonoscopy during endoscopy blocks with one of six high-quality trainers. Trainees performed the insertion with attending supervision. The trainee then performed independent withdrawal and inspection of the proximal colon (cecum to splenic flexure), identifying polyps without attending input. Subsequently, the attending performed a second complete inspection of the proximal colon; polyps that were identified on the second pass were considered missed polyps. RESULTS: In total, 134 patients underwent colonoscopy by 13 gastroenterology trainees over a 17-month period. The overall proximal colon neoplastic (adenoma and serrated) polyp miss rate was 42.6%. Among these, they missed 38.1% of tubular adenomas and 58.9% of sessile serrated polyps in the proximal colon. Approximately 67% of the missed neoplastic polyps were ≤5mm. Trainee AMR and SMR decreased with increasing colonoscopy experience. CONCLUSIONS: Trainees miss over 40% of proximal colon neoplastic polyps, including the majority of right sided sessile serrated polyps. Measuring polyp miss rates using tandem colonoscopy is a novel and feasible approach to objectively assessing colonoscopy quality among gastroenterology trainees.