Abstract: Objective To assess the value of Improved Mayo Endoscopic Score (IMES) for evaluation of treatment efficacy for active ulcerative colitis (UC). Methods We retrospectively analyzed the clinical and endoscopic data of 103 patients diagnosed with active UC in Beijing Tsinghua Changgung Hospital from January, 2015 to December, 2020. The severity of endoscopic lesions was determined by Mayo Endoscopic Score and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and the area of the endoscopic lesions was evaluated based on the Montreal classification system. The IMES was established by combining the MES with the Montreal classification. Results Univariate analysis suggested that young patients (<40 years old), patients with extensive disease type (E3), patients with high endoscopic scores (MES=3, UCEIS>4, and IMES>4), and patients receiving advanced drug therapy (with systemic hormones, immunosuppressants, immunomodulators, and biological agents, etc.) had lower clinical and endoscopic remission rates. COX survival analysis showed that IMES≤4 was an independent risk factor for clinical and endoscopic remission. ROC curve indicated that the predictive value of IMSE≤4 for clinical and endoscopic remission (AUC=0.7793 and 0.7095, respectively; P<0.01) was better than that of Montreal (AUC=0.7357 and 0.6847, respectively; P<0.01), MES=2 (AUC=0.6671 and 0.5929, respectively; P<0.01), and UCEIS≤4 (AUC=0.6823 and 0.6459, respectively; P<0.01); IMES=5 had a better predictive value for patients with active UC undergoing colectomy tham E3 and MES=3. Conclusion IMES has good value in evaluating treatment efficacy for active UC.

Key words: endoscopy; score; ulcerative colitis; efficacy