Validation of the Ulcerative Colitis Colonoscopic Index of Severity and Its Correlation With Disease Activity Measures

Background and AimsEndoscopic healing is likely to become an important goal for treatment of patients with ulcerative colitis (UC). A simple validated endoscopic index is needed. We validated the previously developed UC Colonoscopic Index of Severity (UCCIS).Methods: In a prospective study, 50 patients with UC were examined by colonoscopy; we analyzed videos of rectum and sigmoid, descending, transverse, and cecum/ascending colon. Eight gastroenterologists blindly rated 4 mucosal lesions (for vascular pattern, granularity, friability, ulceration) and severity of damage to each segment and overall. The global assessment of endoscopic severity (GAES) was based on a 4-point scale and 10-cm visual analogue scale. Correlation of the UCCIS score with clinical indexes (clinical activity index and simple clinical colitis activity index), patient-defined remission, and laboratory measures of disease activity (levels of C-reactive protein, albumin, and hemoglobin and platelet counts) were estimated by using the Pearson (r) or Spearman (rs) method. Results: Interobserver agreement was good to excellent for the 4 mucosal lesions evaluated by endoscopy and the GAES. The UCCIS calculated for our data accounted for 74% (R2= 0.74) and 80% (R2= 0.80) of the variation in the GAES and visual analogue scores, respectively (P <.0001). The UCCIS also correlated with clinical activity index (r = 0.52, P <.001), simple clinical colitis activity index (r = 0.62, P <.0001), and patient-defined remission (r = 0.43, P <.01). The UCCIS also correlated with levels of C-reactive protein (rs= 0.56, P <.001), albumin (r = -0.55, P <.001), and hemoglobin (r = -0.39, P <.01). A rederivation of the equation for the UCCIS by using the data from a previous study combined with those of the current study (n = 101) yielded similar results. Conclusions: The UCCIS is a simple tool that provides reproducible results in endoscopic scoring of patients with UC.