Enhancing Endoscopic Scoring Consistency and Accuracy in IBD: a Video-based Training Approach

Endoscopy is a cornerstone in diagnosis, management and monitoring of patients with inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC). Endoscopy in combination with histological assessment plays a crucial role in diagnosis of IBD, distinguishing between UC and CD and ruling out other diseases with similar clinical presentations. The STRIDE-II consensus, developed by the International Organization for the Study of IBD (IOIBD), highlights endoscopic healing as the primary long-term therapeutic goal. Achieving endoscopic healing is associated with improved patient outcomes, including steroid-free remission, a reduced risk of clinical relapse, hospitalization, colectomy, and dysplasia or colorectal cancer.

Endoscopic scoring systems are vital for the objective assessment of disease activity being used in both clinical trials and daily clinical practice. These standardized scoring systems are essential for diagnosing, evaluating endoscopic healing, monitoring treatment response, and predicting clinical outcomes.

The most widely adapted scoring systems in IBD include:

• The Simple Endoscopic Score for Crohn's Disease (SES-CD) evaluates four key parameters: ulcer size, ulcerated surface, affected surface area, and luminal narrowing. It offers a straightforward, clinically validated scoring system that strongly correlates with indices such as the Crohn's Disease Activity Index.
• The updated Rutgeerts Score provides accurate and clinically relevant assessments of postoperative recurrence in CD and facilitates the prediction of clinical and surgical outcomes for patients with an ileocolonic anastomosis.
• The Endoscopic Mayo Score is a component of the broader Mayo scoring system used to assess disease activity in UC. It evaluates the extent and severity of mucosal inflammation, correlating well with clinical outcomes, including treatment response.
• The Ulcerative Colitis Endoscopic Index of Severity (UCEIS) standardizes the evaluation of endoscopic severity in UC. It incorporates more detailed descriptors of mucosal appearance, including vascular pattern, bleeding, erosions, and ulcerations to describe overall disease severity (Neurath & Travis, 2012).
• The Pouchitis Disease Activity Index (PDAI) assesses pouchitis severity using clinical symptoms, endoscopic findings, and histological features of the pouch. This quantitative tool helps to diagnose and monitor pouchitis. Endoscopic part of PDAI (ePDAI) consists of six features describing mucosal changes: oedema, granularity, friability, loss of vascular pattern, mucous exudate and ulceration.
• The Simplified Endoscopic Score for Pouchitis (SES-pouchitis), recently suggested as an alternative to the PDAI, adapts the SES-CD framework to focus on one single segment, namely the ileal pouch.

One of the primary challenges in implementing these scoring systems is inter-observer variability, as highlighted by significant discrepancies between scores assigned by local and central reviewers. However, the performance of these systems among experts has been shown to be excellent, suggesting that achieving consistent and accurate scoring requires a high level of exposure and proficiency.