Endoscopic characterization of small colonic polyps: baseline performance of experienced endoscopists is no different to that of medical students

Background Studies examining the impact of training modules on characterization of diminutive colonic polyps (DCP) show varying results. Aim We aimed to assess the impact of a novel web-based training module on the accuracy of in vivo characterization of DCPs using different imaging modalities. Differences between groups with varying degrees of endoscopic experience were also assessed. Methods In total, 90 images of 30 DCPs viewed with high definition white light (HDWL), i-Scan, and indigo carmine chromoendoscopy were included in an online test module. Testing was undertaken before and after completing a novel web-based in vivo characterization training module. In total, 21 subjects (medical students (MS), gastroenterology trainees (GT), and gastroenterology consultants (GC)) undertook the tests and training module. Results No statistically significant difference in overall accuracy was found between the three groups either pre- (MS 59.1 %, GR 65.7 %, GC 62.4 %, P = ns for all three comparisons) or post-training (MS 69.2 %, GR 71.1 %, GC 71.3 %, P = ns for all three comparisons). Accuracy improved significantly for all three groups post-training (P < 0.001) as did interobserver agreement. No significant differences in accuracy between modalities were found pre-training (HDWL 64.8 %, i-Scan 60.0 %, chromoendoscopy 62.2 %, P = ns). Post-training accuracy with HDWL and chromoendoscopy was better than with i-Scan (HDWL 72.9 % vs i-Scan 65.1 %, P = 0.002; i-Scan 65.1 % vs chromoendoscopy 73.7 %, P < 0.001). The proportion of high confidence predictions increased from 25.7 % to 41.5 %, with a high confidence prediction accuracy of 81.7 %. Conclusions Skills for in vivo characterization of DCPs are not acquired through endoscopic experience alone. A novel web-based training intervention results in modest improvements in accuracy with further improvements likely to require more prolonged training.