Abstract Background Identifying predictors of poor outcomes in paediatric Crohn’s disease (CD) will impact therapeutic strategy. We aimed to define predictors of non-remission during two-year follow-up primary outcome and to predict time to first (TFR), corticosteroid-free (TCSFR, ≥ 3 months corticosteroid CS withdrawal) and sustained remission (TSR, ≥ 6 months) secondary outcome in paediatric CD. Methods We used prospectively collected de-identified data from the ImproveCareNow Registry. We included 6234 paediatric CD patients (18 years) diagnosed between 2007 and 2023. Remission was defined as a short Paediatric CD Activity Index 10 points. Statistical analysis was performed using R version 4.5.0 (2025) with an α of 0.05 using multiple imputation for missing data. Logistic regression was used for the primary outcome (n = 794) to identify predictors at diagnosis, first follow-up visit (0-92 days), six- (152-214 days) and twelve-month visit (334-396 days). Cox regression was performed for the secondary outcome (n = 3290) with two models for TFR and TCSFR: one including baseline predictors only, and one including predictors from baseline and the first visit (≤92 days). For TSR, the model included an additional five-month visit (121–181 days). Results For the primary outcome, 53 out of 794 patients (6.7%) never reached remission after two-year follow-up. In the final model, female sex (OR = 3.117, p = 0.002) and use of ustekinumab one year after diagnosis (OR = 14.697, p 0.001) predicted non-remission, with additional parameters improving predictive performance (Area Under the Curve 0.767, 95% CI 0.687-0.848). For the secondary outcome, mean TFR, TCSFR and TSR were 136, 501 and 323 days respectively. In predicting a longer TFR, two models (n = 1137 and n = 981) showed significant associations for mainly age at diagnosis (HR = 1.040, p 0.001), female sex (HR = 0.808 and HR = 0.821, p = 0.002), extraintestinal manifestations (fever; HR = 0.458, p = 0.029) and the need for infliximab (IFX, HR = 1.150, p = 0.045) at first visit. For TCSFR (n = 2009 and n = 2002), predictors included female sex (HR = 0.850, p 0.001), race (Asian HR = 1.420, White HR = 0.830 p 0.05) and type of treatment at first visit (IFX HR = 1.380, CS HR = 0.722 and immunomodulators HR = 0.870, p 0.05). For TSR (n = 318), age at diagnosis (HR = 1.060, p = 0.005) and BMI z-score (HR = 0.967, p = 0.048) regardless of the visit were predictors. Conclusion Clinical parameters such as female sex, younger age at diagnosis and higher BMI as well as therapeutic strategy are predictors of poor outcomes and are associated with longer time to remission in paediatric CD. This study provides insights that are relevant to the design of predictive tools that can assist clinical decision-making. Conflict of interest: Dr. Van Hecke, Jonathan: No conflict of interest Veereman, Gigi: Advisory Boards Huysentruyt, Koen: No conflict of interest Wauters, Lucas: No conflict of interest Hauser, Bruno: No conflict of interest Cools, Wilfried: No conflict of interest Cleymans, Niels: No conflict of interest Adler, Jeremy: Jeremy Adler is co-chair of the research committee for the ImproveCareNow Network - National collaboration for quality improvement in pediatric inflammatory bowel disease, member of the European Crohn’s and Colitis Organisation (ECCO), member of the Crohn’s and Colitis Foundation, member of the American Gastroenterological Association (AGA) and member of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN). Jeremy Adler received research funding from Janssen Research & Development, which is not related to this study. Shehzad, Saeed: Shehzad Saeed has received research funding from Janssen Research and Development and Helmsley Foundation, which is not relevant to the current study. De Greef, Elisabeth: No conflict of interest
Hecke et al. (Thu,) studied this question.