title: Disease Outcome of Ulcerative Colitis in an Era of Changing Treatment Strategies: Results from the Dutch Population-Based IBDSL Cohort.
abstract: OBJECTIVE
  In the past decades, treatment options and strategies for ulcerative colitis [UC] have radically changed. Whether these developments have altered the disease outcome at population level is yet unknown. Therefore, we evaluated the disease outcome of UC over the past two decades in the South-Limburg area of The Netherlands.
  
  
  METHODS
  In the Dutch population-based IBDSL cohort, three time cohorts were defined: cohort 1991-1997 [cohort A], cohort 1998-2005 [cohort B], and cohort 2006-2010 [cohort C]. The colectomy and hospitalisation rates were compared between cohorts by Kaplan-Meier survival analyses. Hazard ratios [HR] for early colectomy [within 6 months after diagnosis], late colectomy [beyond 6 months after diagnosis], and hospitalisation were calculated using Cox regression models.
  
  
  RESULTS
  In total, 476 UC patients were included in cohort A, 587 patients in cohort B, and 598 patients in cohort C. Over time, an increase in the use of immunomodulators [8.1%, 22.8% and 21.7%, respectively, p < 0.01] and biological agents [0%, 4.3% and 10.6%, respectively, p < 0.01] was observed. The early colectomy rate decreased from 1.5% in cohort A to 0.5% in cohort B [HR 0.14; 95% confidence interval 0.04-0.47], with no further decrease in cohort C [0.3%, HR 0.98; 95% confidence interval 0.20-4.85]. Late colectomy rate remained unchanged over time [4.0% vs 5.2% vs 3.6%, respectively, p = 0.54]. Hospitalisation rate was also similar among cohorts [22.3% vs 19.5% vs 18.3%, respectively, p = 0.10].
  
  
  CONCLUSIONS
  Over the past two decades, a reduction in early colectomy rate was observed, with no further reduction in the most recent era. Late colectomy rate and hospitalisation rate remained unchanged over time.
authors.affiliation: Division of Gastroenterology-Hepatology, Maastricht University Medical Centre+, Maastricht, The Netherlands School of Nutrition and Translational Research in Metabolism [NUTRIM], Maastricht University Medical Centre+, Maastricht, The Netherlands steven.jeuring@maastrichtuniversity.nl.
authors.forename: Steven F G
authors.initials: SF
authors.lastname: Jeuring
authors.affiliation: Division of Gastroenterology-Hepatology, Maastricht University Medical Centre+, Maastricht, The Netherlands School of Nutrition and Translational Research in Metabolism [NUTRIM], Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Paul H A
authors.initials: PH
authors.lastname: Bours
authors.affiliation: Department of Complex Genetics, School of Nutrition and Translational Research in Metabolism [NUTRIM], Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Maurice P
authors.initials: MP
authors.lastname: Zeegers
authors.affiliation: Department of Methodology and Statistics, Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Ton W
authors.initials: TW
authors.lastname: Ambergen
authors.affiliation: Division of Gastroenterology-Hepatology, Maastricht University Medical Centre+, Maastricht, The Netherlands School of Nutrition and Translational Research in Metabolism [NUTRIM], Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Tim R A
authors.initials: TR
authors.lastname: van den Heuvel
authors.affiliation: Department of Internal Medicine and Gastroenterology, Orbis Medical Centre, Sittard-Geleen, The Netherlands.
authors.forename: Mariëlle J L
authors.initials: MJ
authors.lastname: Romberg-Camps
authors.affiliation: Department of Internal Medicine and Gastroenterology, Orbis Medical Centre, Sittard-Geleen, The Netherlands.
authors.forename: Ad A
authors.initials: AA
authors.lastname: van Bodegraven
authors.affiliation: Department of Internal Medicine and Gastroenterology, Atrium Medical Centre, Heerlen, The Netherlands.
authors.forename: Liekele E
authors.initials: LE
authors.lastname: Oostenbrug
authors.affiliation: Department of General Surgery, Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Stéphanie O
authors.initials: SO
authors.lastname: Breukink
authors.affiliation: Department of General Surgery, Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Laurents P S
authors.initials: LP
authors.lastname: Stassen
authors.affiliation: Division of Gastroenterology-Hepatology, Maastricht University Medical Centre+, Maastricht, The Netherlands School of Nutrition and Translational Research in Metabolism [NUTRIM], Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Wim H
authors.initials: WH
authors.lastname: Hameeteman
authors.affiliation: Division of Gastroenterology-Hepatology, Maastricht University Medical Centre+, Maastricht, The Netherlands School of Nutrition and Translational Research in Metabolism [NUTRIM], Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Ad A M
authors.initials: AA
authors.lastname: Masclee
authors.affiliation: Division of Gastroenterology-Hepatology, Maastricht University Medical Centre+, Maastricht, The Netherlands School of Nutrition and Translational Research in Metabolism [NUTRIM], Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Daisy M A E
authors.initials: DM
authors.lastname: Jonkers
authors.affiliation: Division of Gastroenterology-Hepatology, Maastricht University Medical Centre+, Maastricht, The Netherlands School of Nutrition and Translational Research in Metabolism [NUTRIM], Maastricht University Medical Centre+, Maastricht, The Netherlands.
authors.forename: Marieke J
authors.initials: MJ
authors.lastname: Pierik
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003082:Colectomy; D003093:Colitis, Ulcerative / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D005260:Female; D006760:Hospitalization; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D016016:Proportional Hazards Models; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D007155:Immunologic Factors
keywords: Ulcerative colitis; epidemiology; surgery