title: The epidemiology of colectomy in ulcerative colitis: results from a population-based cohort.
abstract: OBJECTIVE
  Previous studies have reported colectomy rates of over 50% in ulcerative colitis (UC), although changes in management may have influenced the rates of colectomy in the modern era. We sought to determine the incidence of colectomy in UC and identify risk factors associated with early colectomy (EC) and late colectomy (LC).
  
  
  METHODS
  We used the University of Manitoba Inflammatory Bowel Disease Epidemiology Database, a population-based data set including UC patients with up to 25 years of post diagnosis follow-up. We tracked the occurrence of total colectomy in all patients with known UC, subdivided into EC (≤90 days from diagnosis date) and LC (>90 days from diagnosis). Survival curves were created and stratified by age, sex, era of diagnosis, and inpatient/hospital diagnosis. Cox proportional hazards modeling was used to determine which risk factors were predictive of either EC or LC.
  
  
  RESULTS
  Among 3,752 patients with UC, 367 underwent colectomy. The 5-, 10- and 20-year actuarial risk of requiring colectomy was 7.5%, 10.4%, and 14.8%, respectively. Male sex (hazard ratio (HR): 2.63, [corrected] 95% confidence interval (CI): 1.58-4.36) and being initially diagnosed during a hospitalization (HR: 12.46, 95% CI: 7.40-21.0) were predictive of EC after adjustment for confounders. In-hospital diagnosis was predictive of LC, whereas being diagnosed more recently was protective against LC (HR: 0.96, 95% CI: 0.93-0.98).
  
  
  CONCLUSIONS
  The cumulative incidence of colectomy in UC is lower than previously reported, and appears to be decreasing further among more recently diagnosed cohorts of patients. Male sex and hospitalization at the time of diagnosis are major risk factors for EC and LC.
authors.affiliation: Section of Gastroenterology, Department of Internal Medicine, University of Manitoba IBD Clinical and Research Centre, Winnipeg, Canada. targowni@cc.umanitoba.ca
authors.forename: Laura E
authors.initials: LE
authors.lastname: Targownik
authors.forename: Harminder
authors.initials: H
authors.lastname: Singh
authors.forename: Zoann
authors.initials: Z
authors.lastname: Nugent
authors.forename: Charles N
authors.initials: CN
authors.lastname: Bernstein
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003082:Colectomy / Q000706:statistics & numerical data*; D003093:Colitis, Ulcerative / Q000175:diagnosis / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors