The Ulcerative Colitis Endoscopic Index of Severity More Accurately Reflects Clinical Outcomes and Long-term Prognosis than the Mayo Endoscopic Score.

Background And Aims: The Ulcerative Colitis Endoscopic Index of Severity (UCEIS) and the Mayo endoscopic score (Mayo ES) are used to evaluate ulcerative colitis (UC) severity. This study compared UCEIS and the Mayo ES for evaluating UC severity and outcomes in patients undergoing remission induction during routine clinical practice with the aim of predicting medium- to long-term prognosis.

Methods: Forty-one UC patients who received colonoscopy before and after tacrolimus remission induction therapy were included. An index of clinical activity and endoscopic findings scored by both the UCEIS and the Mayo ES were determined. Changes in UCEIS and Mayo ES before and after induction therapy were compared.

Results: The mean UCEIS improved from 6.2±0.9 to 3.4±2.1 (p < 0.001). Based on the UCEIS, a significant reduction was reached in both the response and the remission groups. In contrast, the Mayo ES did not reflect a significant change in the response group. The discrepancy appeared to be due to ulcers becoming smaller and shallower during the early stages of mucosal healing; the Mayo ES seems to miss these early changes. In other words, whereas the UCEIS indicates improvements when ulcers shrink, the Mayo ES does not distinguish deep ulcers from shallow ulcers and is 3 (severe UC) for both deep and shallow ulcers. Additionally, better UCEIS strata after induction therapy were associated with lower incidences of colectomy (p = 0.0001) or relapse (p = 0.0008).

Conclusions: The UCEIS accurately reflects clinical outcomes and predicts the medium- to long-term prognosis in UC patients undergoing induction therapy. These findings should support decision-making in clinical practice settings.