Predictors of Complicated Disease Course in Adults and Children With Crohn's Disease: A Nationwide Study from the epi-IIRN.

ABSTRACT

BACKGROUND: Since data on predictors of complicated Crohn's disease (CD) from unselected populations are scarce, we aimed to utilize a large nationwide cohort, the epi-IIRN, to explore predictors of disease course in children and adults with CD. METHODS: Data of patients with CD were retrieved from Israel's 4 health maintenance organizations, whose records cover 98% of the population (2005-2020). Time-to-event modeled a complicated disease course, defined as CD-related surgery, steroid-dependency, or the need for >1 class of biologics. Hierarchical clustering categorized disease severity at diagnosis based on available laboratory results. RESULTS: A total of 16 659 patients (2999 [18%] pediatric-onset) with 121 695 person-years of follow-up were included; 3761 (23%) had a complicated course (750 [4.5%] switched to a second biologic class, 1547 [9.3%] steroid-dependency, 1463 [8.8%] CD-related surgery). Complicated disease was more common in pediatric- than adult-onset disease (26% vs 22%, odds ratio, 1.3; 95% confidence interval [CI], 1.2-1.4). In a Cox multivariate model, complicated disease was predicted by induction therapy with biologics (hazard ratio [HR], 2.1; 95% CI, 1.2-3.6) and severity of laboratory tests at diagnosis (HR, 1.7; 95% CI, 1.2-2.2), while high socioeconomic status was protective (HR, 0.94; 95% CI, 0.91-0.96). In children, laboratory tests predicted disease course (HR, 1.8; 95% CI, 1.2-2.5), as well as malnutrition (median BMI Z score -0.41; 95% CI, -1.42 to 0.43 in complicated disease vs -0.24; 95% CI, -1.23 to 0.63] in favorable disease; P < .001). CONCLUSIONS: In this nationwide cohort, CD course was complicated in one-fourth of patients, predicted by laboratory tests, type of induction therapy, socioeconomic status, in addition to malnutrition in children.

Prognostic factors of complicated disease course are vital for considering early escalation to biologics. In this nationwide cohort, complicated disease course was apparent in approximately one-fourth of patients and was predicted particularly by routinely collected laboratory tests, age, and type of induction therapy at diagnosis.