Risk factors at diagnosis for progression to severe colitis and colectomy in children and young adult patients with mild‐moderate disease

Abstract Objectives Pediatric ulcerative colitis (UC) has a more severe and unpredictable course than adult‐onset disease. This study aimed to identify baseline and time‐varying risk factors for the development of severe disease or colectomy among children and young adults with mild to moderate UC. Methods We conducted a retrospective analysis using data from ImproveCareNow (ICN), a multicenter pediatric inflammatory bowel disease registry (2009–2019). Inclusion criteria were UC diagnosis within 3 months of enrollment, age <21 years, at least 1 year of follow‐up, pediatric ulcerative colitis activity index (PUCAI) score at each visit and mild to moderate disease. Cox proportional hazard models were fit to analyze risk factors for developing a severe outcome, defined as PUCAI ≥ 65 or colectomy. Results Out of 13,075 patients with UC, 1401 met inclusion criteria, among whom 165 (11.8%) patients developed a severe outcome (125 9% with PUCAI≥65; 40 2.8% with colectomy). Each 15‐point increase in PUCAI at enrollment conferred a 1.52 times increased risk of having a severe outcome (95% confidence interval CI for hazard ratio HR: 1.28–1.81; p < 0.0001). Use of systemic steroids significantly increased the risk (HR: 13.61; 95% CI: 9.01–20.56; p < 0.0001) as did budesonide (HR: 4.77; 95% CI: 2.39–9.50; p < 0.0001). Use of oral aminosalicylates (HR: 0.46; 95% CI: 0.31–0.70; p = 0.0002) and immunomodulators (HR: 0.56; 95% CI: 0.36–0.89; p = 0.01) was associated with reduced risk. Black patients had a higher risk of developing a severe outcome compared to White patients (HR: 1.74; 95% CI: 1.01–2.99; p = 0.047). Conclusions Steroid use, higher PUCAI, and Black race were associated with elevated risk of a severe outcome, while immunomodulators or oral aminosalicylates use was associated with decreased risk. These factors should be considered when developing treatment plans.