Differences between childhood- and adulthood-onset inflammatory bowel disease: the CAROUSEL study from GETECCU

Background Cohort studies comparing the characteristics of childhood-onset and adulthood-onset inflammatory bowel disease (IBD) in the biologics era are scarce. Aim To compare disease characteristics, the use of immunomodulators and biologic agents and the need for surgery between childhood- and adulthood-onset IBD. Methods Inflammatory bowel disease patients from the ENEIDA registry diagnosed between 2007 and 2017 were included. The childhood-onset cohort comprised patients diagnosed at 16 years. The cumulative incidences of immunosuppressive therapy, biologic therapy and surgery were estimated using Kaplan-Meier curves, compared by the log-rank test. Cox regression analysis was performed to identify potential predictive factors of treatment with immunosuppressants, biologic agents or surgery. Results The adulthood-onset cohort comprised 21 200 patients out of 20 354 (96%) and the childhood-onset cohort 846 (4%). Median follow-up was 54 months in the childhood-onset cohort and 38 months in the adulthood-onset cohort (P < 0.01). Proportions of Crohn's disease, ileocolonic involvement and inflammatory behaviour at diagnosis were higher in the childhood-onset cohort. In the multivariate analysis, after adjusting for sex, type of IBD, extraintestinal manifestations, family history and smoking habit, childhood-onset IBD was associated with higher risk of immunomodulator use (hazard ratio [HR] = 1.2, 95% confidence interval [95% CI] = 1.1-1.2) and higher probability of receiving biologic treatment (HR = 1.2, 95% CI = 1.1-1.3). However, childhood-onset IBD was not associated with higher risk of surgery (HR = 0.9, 95% CI = 0.8-1.2). Conclusions Childhood-onset IBD has differential characteristics and higher risk of treatment with immunomodulators and biologic agents, compared with adulthood-onset IBD. Nevertheless, paediatric IBD is not associated with higher risk of surgery.