Abstract Background The global burden of ulcerative colitis (UC) remains incompletely characterised. This study primarily evaluated global UC incidence and prevalence. Methods A systematic review included observational studies (cohort, cross-sectional, case-controlled), systematic reviews, and conference abstracts directly reporting UC incidence or prevalence. MEDLINE and EMBASE were searched. The study population comprised adults with mild-to-severe UC between 2014–2025. Study selection followed predefined criteria. One reviewer conducted selection and data extraction, confirmed by a second. Microsoft Excel was used for data management. Results A total of 197 studies were included: 177 cohort (prospective or retrospective), 13 cross-sectional, 4 case-control, 1 structured survey, and 2 unspecified designs. Reporting of disease severity was limited, with only 18 studies including the UC Montreal classification Incidence (per 100,000 person-years) ranged globally from 1.16 in Taiwan to 57 in Denmark. Taiwan in Asia reported the lowest incidence (1.16), followed by Brazil (1.34), Spain (2.37), Israel (15.80), Canada (12.90), South Korea (29.71), and Denmark (57.00). Longitudinal data from Italy, Spain, and Denmark demonstrated rising trends, with Spain’s incidence more than doubling over 30 years. Prevalence (per 100.000 person-years) ranged from 11.00 in China to 397.0 in Denmark. The lowest rates were observed in China (11.00) and Brazil (11.90), followed by Spain (36.60), the United States (159.50), South Korea (334.00), and Denmark (397.00). Among populations with comorbidities other than IBD, UC prevalence was generally below 10%. Conclusion UC incidence and prevalence vary widely across regions, with the highest burden observed in Europe, North America, and South Korea. The increasing global trend highlights the need for strengthened surveillance, optimized management strategies, and expanded research to address this growing public health concern. Conflict of interest: Landeira, Margarita: An employee of Ferring Pharmaceuticals with shares in Novo Nordisk as well as Jazz Pharmaceuticals. Markert, Marie: Was a Ferring employee at the time of this study and is a current employee of Pharmacosmos. Guedes, Sandra: Was a Ferring employee at the time of this study and is a current employee of Novartis. Balijepalli, Chakrapani: A contracted partner of Ferring Pharmaceuticals Druyts, Eric: A contracted partner of Ferring Pharmaceuticals. Nielsen, Lasse: Was a Ferring employee at the time of this study.
Landeira et al. (2026) studied this question.