Validity Evidence for an Objective Scoring Tool for Endoscopic Tip Control During Snare Tip Soft Coagulation

Background: And aims Tip control is a core endoscopic skill, yet objective, practical in-vivo assessment tools are lacking. We developed and gathered validity evidence for a scoring method using snare-tip soft coagulation (STSC) of the post-endoscopic mucosal resection (EMR) defect margin as a standardised task. Methods: Prospective, single-center observational study of consecutive patients undergoing EMR for large (>=20 mm) non-pedunculated colorectal polyps. Live or video observers used a web-tool to classify STSC applications as correct ("on-margin") or incorrect. Outcomes were accuracy, speed (correct hits/minute), z-standardised composite score (z_accuracy + z_speed = performance index) and rater subjective impression. Group differences (experts >500 EMRs vs trainees <50 EMRs) were estimated with generalised linear mixed-effects models, with random intercepts for endoscopist, observer, and procedure. Inter-rater reliability was calculated (ICC(2,k)). NCT05660317 RESULTS: Sixty-eight procedures performed by 14 endoscopists were scored by 19 observers (170 ratings; median 2 per procedure, IQR 1-3). Experts (n=3) outperformed trainees (n=11) for accuracy (adjusted mean 90.0% vs 81.2%; adjusted mean difference [AMD] +8.9 percentage points [95% CI 4.6-12.9]; P<.001) and speed (13.3 correct hits/minute [95% CI 11.0-15.6] vs 9.7 [95% CI 8.0-11.4]; AMD +3.6 correct hits/min [95% CI 0.9-6.3]; P=0.01). The performance index for experts was significantly higher than for trainees (AMD +1.4 [95% CI 0.7-2.2], P<0.001). Overall impression scores also favored experts (AMD +1.0 points on 0-10 scale [95% CI 0.5-1.6]; P<.001). Inter-rater reliability for overall impression and accuracy was excellent (ICC[2,k] = 0.98 and 0.97 respectively). Convergent validity was demonstrated by significant associations between overall impression and both accuracy (beta=0.8 per 10 percentage points [95% CI 0.7-1.0]; P<.001) and speed (beta=0.7 per 10 hits/min [95% CI 0.4-1.0]; P<.001). Conclusions: A simple, in-vivo, procedure-level score captured during routine STSC provided an objective measure of endoscopic tip control, separating experts from trainees.

Citation

Desomer et al (2026). Validity Evidence for an Objective Scoring Tool for Endoscopic Tip Control During Snare Tip Soft Coagulation. Gastrointestinal endoscopy, S0016-5107(26)06745-3. Advance online publication. https://doi.org/10.1016/j.gie.2026.05.010

DOI

10.1016/j.gie.2026.05.010

URI

https://hdl.handle.net/20.500.14709/1476