Inter-observer agreement in endoscopic scoring systems: Preliminary report of an ongoing study from the Italian Group for Inflammatory Bowel Disease (IG-IBD)

Abstract

BackgroundEndoscopic activity has become a therapeutic endpoint in inflammatory bowel disease. Aim of this study was to evaluate inter-observer agreement for endoscopic scores in a real-life setting. Methods14 gastroenterologists with experience in inflammatory bowel disease care and endoscopic scoring reviewed videos of ulcerative colitis (n=13) and postoperative (n=10) and luminal (n=8) Crohn's disease. The Mayo subscore for ulcerative colitis, Rutgeerts score for postoperative Crohn's disease, Crohn's disease endoscopic index of severity (CDEIS), and the simple endoscopic score-Crohn's disease (SES-CD) for luminal Crohn's disease were calculated. A subset of five endoscopic clips were assessed by 30 general gastroenterologists without specific experience in endoscopic scores. Kappa statistics and intraclass correlation coefficients were used to measure agreement. ResultsMayo subscore agreement was suboptimal: kappas were 0.53 (95% confidence interval 0.47–0.56) and 0.71 (0.67–0.76) for the two groups. Rutgeerts score agreement was fair: kappas were 0.57 (0.51–0.65) and 0.67 (0.60–0.72). Agreements for CDEIS and SES-CD were good: intraclass correlation coefficients for the two groups were 0.83 (0.54–1.00) and 0.67 (0.36–0.97) for CDEIS and 0.93 (0.76–1.00) and 0.68 (0.35–0.97) for SES-CD, respectively. ConclusionThe reproducibility of endoscopic scores in inflammatory bowel disease remains suboptimal, which could potentially have major effects on therapeutic choices.