Trends in the epidemiology of inflammatory bowel disease among Jewish Israeli adolescents: a population-based study

Background: The incidence and prevalence trends of inflammatory bowel disease (IBD) vary between developed and developing countries. Aim: To investigate the prevalence and associated sociodemographic factors of IBD in Israeli Jewish adolescents. Methods: The files of the army medical corps were reviewed for adolescents recruited in 2002-2016 with confirmed IBD. Covariate data included birth date, patient and parental country of birth, number of children in the household, age at diagnosis, and socioeconomic status. Findings were compared with the remaining recruits without IBD. Results: Of the 1,144,213 adolescents recruited, 2372 (0.2%) had IBD (Crohn's disease, 68%). Median age of the cohort was 17.1 years (interquartile range, 16.9-17.3). Over the study period, the annual point prevalence per 100,000 examinees significantly increased: total IBD, 58 to 373; Crohn's disease, 42 to 425; ulcerative colitis, 16 to 128. Mean age at IBD diagnosis decreased from 15.0 ± 2.8 years in 2002-2008 to 14.3 ± 3.1 years in 2009-2016 (P < 0.0001). Significance was maintained on separate analyses of Crohn's disease and ulcerative colitis. Both diseases were significantly less prevalent in subjects from families with at least one parent born in a developing country and ≥3 children. There was a significant association of lower socioeconomic status with lower prevalence of Crohn's disease (odds ratio 0.41, 95% confidence interval, 0.31-0.54) and ulcerative colitis (odds ratio 0.25, 95% confidence interval, 0.15-0.42). Conclusions: The point prevalence of Crohn's disease and ulcerative colitis in Israeli Jewish adolescents increased six-fold and eight-fold, respectively, over 15 years along with a decrease in age at diagnosis.