The incidence of inflammatory bowel disease in a rural region of Southern Germany:: a prospective population-based study

Objective Although important advances in understanding the aetiology and pathogenesis of inflammatory bowel disease (IBD) have been made, many questions remain unanswered. As the most recent data available on the incidence of IBD in Germany were collected about 15 years ago, we set up a new population-based cohort to determine current incidence data for a defined region in Germany and to establish a basic cohort for prospective follow-up. Methods All patients living in the region of Oberpfalz newly diagnosed with IBD between 1 January 2004 and 31 December 2006 were included in this study by setting up a network of reporting clinicians and general practitioners in hospitals as well as in private practices. Demographic and clinical characteristics such as age at first diagnosis, localization of the disease, extraintestinal manifestations or family history on IBD were documented. Age-adjusted incidence rates are presented with 95% Poisson confidence intervals (CIs), based on the European standard population. Results In total, 286 newly diagnosed patients with IBD were reported in this region, 168 patients suffering from Crohn's disease (CD), 105 patients with ulcerative colitis. Age-standardized incidence rates were 11.0/10(5) (95% Cl: 9.1-11.6) for IBD, 6.6/10(5) (95% Cl: 5.6-77) for CD and 3.9/10(5) (95% CI: 3.2-4.7) for ulcerative colitis. Peak incidences were found in the age interval of 16-24 years for both diseases, predominantly for CID. Age at first diagnosis was lower, extraintestinal manifestations and a positive family history on IBD were more common in patients with CD. Conclusion The incidence rate in IBD seems to be stable in Germany as compared with previously reported data, as is the remarkable predominance of CD. Prospective follow-up studies will be based on this incidence cohort.