Increasing incidence and lifetime risk of inflammatory bowel disease in Taiwan: A nationwide study in a low-endemic area 1998-2010

Background: The incidence of inflammatory bowel disease is increasing worldwide, but data of epidemiological trends from low-endemic area are limited. As one of the low-endemic countries, we describe the trends of this disease in Taiwan over time. Methods: This study was based on data obtained from the Catastrophic Illnesses Registration in the National Health Insurance Research Database, which covers more than 98% of the people in Taiwan. Every certificate of catastrophic illness must be approved by 2 expert gastroenterologists. Thirteen years (1998-2010) of data were analyzed for the trends of Crohn's disease (CD) and ulcerative colitis (UC). Results: A total of 2915 incident cases (1818 men and 1097 women) were identified, including 2357 cases of UC and 558 cases of CD. The mean annual incidence rates were 0.80 for UC and 0.19 for CD per 100,000 inhabitants, with lifetime risks for those 20 to 79 years of age of 0.066% and 0.013%, respectively. The mean annual prevalence was 4.59 for UC and 1.05 for CD per 100,000 inhabitants. Poisson regression showed significantly increased trends during the observation period for both diseases, with a men/women ratio of 1.50 in UC and 2.14 in CD (P < 0.01). The mean age of individuals at diagnosis was higher for UC as compared with CD (44.7 versus 37.9, P < 0.001). Conclusions: Inflammatory bowel diseases are still relatively uncommon in Taiwan, but the incidence and prevalence rates are increasing.