Risk of colectomy is decreasing among newly diagnosed Finnish ulcerative colitis patients

Background and Aims The risk of colectomy in patients with ulcerative colitis (UC) has decreased since the 20th century. Our aim was to determine the colectomy risk of newly diagnosed Finnish UC patients and compare the risk of the prebiological and biological era. Methods We used the registry of the Social Insurance Institution of Finland to find newly diagnosed UC patients, and colectomies were collected from the Finnish Institute for Health and Welfare. The patients were stratified according to the year of UC diagnosis into 3 groups: 2000-2005 (prebiological), 2006-2012, and 2013-2020. Results We identified 32 108 UC patients and 2195 colectomies performed on them. The 1-, 5-, and 10-year cumulative colectomy risk was 1.0%, 4.7%, and 7.3%, respectively. The risks declined with the incidence rate ratio (IRR) 0.98 (95% CI, 0.96-0.99), IRR 0.97 (CI, 0.96-0.98), and IRR 0.97 (CI, 0.96-0.99), respectively. Men and the pediatric group had higher risk of surgery (IRR 1.25, CI, 1.15-1.37 and IRR 1.69, CI, 1.51-1.89). Colectomy risks were lower in the last study era (IRR 0.757, CI, 0.574-0.997 in 1-year and IRR 0.70, CI, 0.61-0.82 in 5-year risk), and the 10-year risk was also decreased in the second era (IRR 0.87, CI, 0.78-0.97) compared to the prebiological era. The pediatric population had lower risk of surgery only in the last era, whereas the risk among the elderly remained constant. Conclusions The risk of colectomy in UC patients has decreased in the 21st century.