228 Incidence and geographical variability of pediatric inflammatory bowel disease in Croatia: data from the Croatian national registry. (11th October 2021) - Ivković, Lana
Abstract : Primary aims of this study were to determine the annual incidence and geographic distribution of pediatric inflammatory bowel disease (IBD), respectively existence of north to south gradient in Croatia as well as baseline characteristics at the time of diagnosis. Secondary aim was to compare data on frequency and distribution of pediatric IBD in two consecutive years. This is a prospective, cohort, multicenter observational study based on the data obtained from the newly established Croatian national registry for children with inflammatory bowel disease. Children and adolescents younger than 18 years diagnosed with IBD, according to revised Porto criteria, in time period between June 1st, 2016 and May 31st, 2017 were recruited. In order to validate obtained data and to monitor trends in the incidence of the disease, the data were also gathered for the period from June 1st, 2017 to May 31st, 2018. In season 2016/2017, 51 new cases of pediatric IBD were identified; 19 (37.3%) Crohn's disease (CD), 28 (54.9%) ulcerative colitis (UC) and 8 (7.8%) IBD unclassified (IBD-U). Male preponderance of all three types of the disease was noticed (CD 52.6%, UC 60.7%, IBD-U 75%). The median age at diagnosis was 14.8 years; 15.3 for CD, 13.9 for UC, and 14.5 years for IBD-U. Female patients were slightly older than males, but without statistically significant difference (p=0.279). With 723, 552 children younger than 18 years in Croatia in 2017, the annual incidence of pediatric IBD per 100, 000 persons per year was 7.05 (2.62 for CD, 3.87 of UC and 0.55 for IBD-U). The lowest incidence was found in Dubrovnik-Neretva and Split-Dalmatia County (4.50-4.85/100, 000 children up to 18 years of age/year), and the highest was found in Meðimurje County (22.80/100, 000 children up to 18 years of age/year). Existence of north to south gradient was observed with almost two times higher incidence in northern region compared with southern parts of the country (8.38/100, 000 vs. 4.26/100, 000). Data from consecutive season (2017/2018) identified 50 new cases of pediatric IBD, with higher proportion of CD (44%) compared to year before. The incidence of pediatric IBD in Croatia is 7.05 per 100, 000 persons younger than 18 years per year, with significant decreasing trend in incidences between northern and southern regions of the country.