An Optimized Patient-reported Ulcerative Colitis Disease Activity Measure Derived from the Mayo Score and the Simple Clinical Colitis Activity Index

Background: There is a need for simple, noninvasive patient-driven disease assessment instruments in ulcerative colitis (UC). We sought to further assess and refine the previous described 6-point Mayo score. Methods: A cross-sectional study of 282 UC patients was conducted assessing the correlation of the 2 patient-reported Mayo score components (6-point Mayo score) with the simple clinical colitis activity index (SCCAI) and a single Likert scale of patient-reported disease activity. Spearman's correlation, sensitivity, specificity, and area under the receiver operating curves (AUC) were calculated. A separate validation study in 59 UC patients was also conducted. Results: Participants predominantly had long-standing disease (83%) and were in self-reported remission (63%). The 6-point Mayo score correlated well with the SCCAI (rho = 0.71; P < 0.0001) and patient-reported disease activity (rho = 0.65; P < 0.0001). Using a cutpoint of 1.5, the 6-point Mayo score had 83% sensitivity and 72% specificity for patient-defined remission, and 89% sensitivity and 67% specificity for SCCAI-defined remission (score, <2.5). The 6-point Mayo score and SCCAI had similar accuracy of predicting patient-defined remission (AUC = 0.84 and 0.87, respectively). Addition of the SCCAI general well-being question to the 6-point Mayo improved the predictive ability for patient-defined remission; and a new weighted score had an AUC of 0.89 in the development cohort and 0.93 in the validation cohort. The optimal cutpoint was 1.6. Conclusions: The patient-reported UC severity index that includes stool frequency, bleeding, and general well-being accurately measures clinical disease activity without requiring direct physician contact.