Background: The Ulcerative Colitis Endoscopic Index of Severity (UCEIS) is a validated endoscopic tool which measures the worst disease activity in the rectosigmoid. This is potentially problematic as paediatric disease is often pancolonic and inflammation can be patchy, especially during active treatment. To date, there are no data evaluating the UCEIS in paediatrics. Using colonoscopy videos performed in patients from the Canadian Children IBD Network, we explored the reliability of the UCEIS when applied to colonic segments proximal to the recto-sigmoid.
Methods: Video recordings of colonoscopies obtained from paediatric patients with UC undergoing endoscopic assessment at Network sites were utilised for the analysis. 4 IBD experts reviewed each video blinded to clinical information. For each anatomic colonic segment data encompassing the 3 elements of the UCEIS (bleeding, ulceration, vascular pattern) were recorded. Total UCEIS scores were calculated for each segment. In addition, the most distal segment with the highest score was identified (UCEIS-max). A global assessment of endoscopic lesion severity for the entire colon (GELS) was also recorded using a visual analogue scale. Inter-rater reliability (IRR) was measured using Intraclass correlation coefficients (ICCs). Correlation between scoring tools was measured using Spearman's test of correlation (r).
Results: There was a broad range of endoscopic severity (median UCEIS 6 (range 3–8). The IRR for each aspect of the UCEIS are displayed in Table 1. The tool performed well throughout the colon, with “bleeding” being the variable demonstrating the most disagreement. When comparing standard UCEIS and UCEIS-max, in 33% of patients the maximally affected segment was proximal to the rectosigmoid. In 10% of these subjects the difference in UCEIS score was greater than 1 point (p<0.001). Correlation with GELS was better for UCEIS-max (r=0.79, p<0.001), than for standard UCEIS (r=0.68, p<0.001).
Conclusions: UCEIS is a valuable tool in the assessment of endoscopic disease severity in paediatric UC. UCEIS, when applied in standard fashion to the recto-sigmoid shows excellent IRR amongst IBD physicians. The tool can be applied across the colon, with only a small decrease in consistency. In this group of patients diagnosed with UC, one third of patients will have the maximally affected area proximal to the rectosigmoid, highlighting the importance of complete colonoscopy in assessing disease activity in UC.