Su1313 Epidemiology and Characteristics of Inflammatory Bowel Disease in a Large Population-Based Cohort in the Netherlands

Abstract

Background and aims: The epidemiology of inflammatory bowel disease (IBD) is changing. In Europe, recent incidence and prevalence rates are lacking. The primary objective of this study is to update incidence and prevalence figures in a large well-phenotyped populationbased IBD cohort.Methods: All IBD patients living in the adherence area of 2 non-academic hospitals between 20042010 were identified. Patients were searched in 3 independent hospital databases case finding sources. 1378 Possible IBD cases were scrutinized, IBD diagnosis was based on established clinical, endoscopic and pathologic criteria. Location and behaviour of IBD was reported according to the Montreal classification. Results: 768 IBD patients were included. 255 (33.2%) patients were diagnosed with Crohn's disease (CD), 432 (56.3%) with ulcerative colitis (UC) and 81 (10.5%) with IBD-Unspecified (IBDU). The male-female ratio of IBD was 1:1.3 (P<0.001). The mean incidence for IBD was 28.0 per 100,000 inhabitants per year; 7.4 for CD, 17.4 for UC and 3.3 for IBD-U. The point prevalence on 01-01-2009 was 345.7 per 100,000 inhabitants; 113.3 for CD, 194.8 for UC and 37.6 for IBD-U. A peak in the mean age-specific incidence for CD was found at the age of 2125 years. For UC 3 peaks were found at the age of 2125, 5155, and 6165 years. In CD, 64 patients (25%) had ileitis without colitis, 91 patients (35.7%) had a colitis, 86 patients (33.7%) had an ileocolitis. 14 Patients (5.5%) had upper GI involvement. Nonstricturing, nonpenetrating behaviour of CD was found in 139 patients (54.5%), stricturing, nonpenetrating was found in 59 (23.1%) patients, penetrating was found in 53 (20.8%) patients. 118 UC patients (27.3%) had a proctitis, 189 patients (43.8%) a left-sided colitis and 124 patients (28.7%) a pancolitis. Male patients had a more extensive UC than female patients (P= 0.003). Conclusion: The population based incidence for IBD was: 28.0 per 100,000 inhabitants per year, with a point prevalence of 345.7 per 100,000 inhabitants. In UC, male patients have a more extensive colitis than female patients.