Epidemiology of diagnosed inflammatory bowel disease in Taiwan population from 2011 to 2021: a population-based study

BACKGROUND: Inflammatory bowel disease (IBD) has shown a steadily rising prevalence in Asian populations over recent decades, coinciding with rapid industrialization, Westernized dietary habits, and lifestyle changes. This study aimed to report the annual trends and sociodemographic-specific rates of the prevalence and incidence of diagnosed IBD in Taiwan from 2011 to 2021. METHODS: A population-based study of all residents enrolled in the National Health Insurance (NHI) program, the Catastrophic Illness Patient Database, was conducted to identify patients diagnosed with IBD. The annual prevalence and incidence of diagnosed IBD were identified using International Classification of Diseases, Ninth and Tenth Revision, Clinical Modification (ICD-9-CM and ICD-10-CM) diagnostic codes, stratified by age, sex, insurance premium, and degree of urbanization. Logistic regression analyses were performed to estimate odds ratios for associated risk factors; while Joinpoint regression analyses were used to assess temporal trends in age-standardized annual prevalence and incidence from 2011 to 2021. RESULTS: The age-standardized annual prevalence of IBD more than doubled from 9.56 per 100,000 persons in 2011 to 19.54 per 100,000 in 2021 (annual percent change [APC]: 7.35%), while incidence rates rose from 0.89 to 2.46 per 100,000 persons over the same period (APC: 11.04%). Males consistently showed higher prevalence and incidence rates than females throughout the study period. Prevalence was highest among individuals aged 50-60 years, those with high income levels, and residents of highly urbanized areas, whereas incidence peaked in the 40-50-year age group and was also elevated among individuals with high income. CONCLUSIONS: Nationwide NHI data showed a substantial increase in IBD prevalence and incidence in Taiwan from 2011 to 2021, with a disproportionately increased burden among men, middle-aged individuals, high-income groups, and residents of highly urbanized areas.