The ImproveCareNow registry: Prediction of 2-year nonremission in pediatric ulcerative colitis.

OBJECTIVE

Identifying predictors of unfavorable disease course in pediatric ulcerative colitis (UC) will impact therapeutic strategy. We aimed to define predictors of nonremission 2 years after diagnosis in pediatric patients with UC.

METHODS

This retrospective analysis of prospectively collected data from ImproveCareNow included pediatric UC patients (<18 years) diagnosed between 2007 and 2023 with at least a 2-year follow-up. Remission was defined as a pediatric UC activity index (PUCAI) < 10 points. Statistical analysis was performed using the International Business Machines Corporation Statistical Package for the Social Sciences (SPSS) version 29. Demographic information at diagnosis/enrollment (T0), first visit (T1) and follow-up (T2, closest to 24 months) were calculated between relevant groups. Binary logistic regression was used to identify outcome predictors. Multiple imputation was used for missing data. This study was approved by the Ethics Committee (Protocol 23135-ICN_UC).

RESULTS

We included 1290 pediatric UC patients. Two years after diagnosis, 390 patients (30%) were not in remission at T2. Differences in disease severity and treatment were observed at T1 and T2. PUCAI (mild odds ratio [OR] = 1.946, moderate OR = 1.735, or severe disease OR = 3.183, p < 0.01), the use of immunomodulators (IM) (OR = 0.631, p = 0.053) and body mass Index (BMI) z-score (OR = 1.149, p = 0.022) at T1 (mean 30 days) predicted non-remission at T2 with poor discriminating ability (area under the curve 0.599-0.621).

CONCLUSION

Predictors for unfavorable disease course were increasing disease severity according to PUCAI (vs. inactive disease), increasing BMI z-score (per z-score increase) and nonuse of IM at T1. These predictors may impact therapeutic strategy shortly after diagnosis.