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

Summary 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 of age and the adulthood‐onset cohort those 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.