Supplementary Material for: Role of Ulcerative Colitis Endoscopic Index of Severity (UCEIS) versus Mayo Endoscopic Subscore (MES) in Predicting Patients′ Response to Biological Therapy and the Need for Colectomy

Background: The main goal in the treatment of ulcerative colitis (UC) is to achieve mucosal healing. Despite being unvalidated, the most widely used scoring system is the Mayo endoscopic subscore (MES). However, the recently established and validated Ulcerative Colitis Endoscopic Index of Severity (UCEIS) represents an interesting alternative method in assessing endoscopic disease activity. Objective: Due to a lack of reliable prognostic factors, the aim of this study was to investigate the diagnostic accuracy of the UCEIS and the MES, in predicting response to biological therapy and the need for colectomy. Methods: We conducted a retrospective, uncontrolled, single-center study on UC patients with endoscopically active disease even with concomitant conventional and/or biological therapy, who had already started or had been changed a biological treatment. Results: Sixty-one UC patients were enrolled. At baseline, 71% were naive to biological therapies and 41% had an extensive colitis. At control time (median time of 11.5 months), MES and UCEIS scores significantly decreased from those at baseline (from 2.6 to 1.8 and 5 to 3.2, respectively, p < 0.001). UCEIS, but not MES, was found to be significantly associated with unresponsiveness to therapy (p = 0.040). Moreover, when UCEIS was ≥7, all patients underwent colectomy after a median time of 5 months (p < 0.001). Conclusion: UCEIS may be superior to MES because of its accuracy and predictive role. Therefore, UCEIS should be considered for use in daily clinical practice.