Systematic review with meta-analysis: proximal disease extension in limited ulcerative colitis

Abstract

Background: Disease extent in ulcerative colitis is one of the major factors determining prognosis over the long-term. Disease extent is dynamic and a proportion of patients presenting with limited disease progress to more extensive forms of disease over time. Aim: To perform a systematic review and meta-analysis of epidemiological studies reporting on extension of ulcerative colitis to determine frequency of disease extension in patients with limited ulcerative colitis at diagnosis. Methods: We performed a systematic literature search to identify studies on disease extension of ulcerative colitis (UC) and predictors of disease progression. Results: Overall, 41 studies were eligible for systematic review but only 30 for meta-analysis. The overall pooled frequency of UC extension was 22.8% with colonic extension being 17.8% at 5 years and 31% at 10 years. Extension was 17.8% (95% CI 11.2-27.3) from E1 to E3, 27.5% (95% CI 7.6-45.6) from E2 to E3 and 20.8% (95% CI 11.4-26.8) from E1 to E2. Rate of extension was significantly higher in patients younger than 18 years (29.2% (CI 6.4-71.3) compared to older patients (20.2% (CI 13.0-30.1) (P