title: Risk factors for complications in patients with ulcerative colitis.
abstract: BACKGROUND
  Patients with ulcerative colitis may develop extraintestinal manifestations like erythema nodosum or primary sclerosing cholangitis or extraintestinal complications like anaemia, malabsorption or they may have to undergo surgery.
  
  
  OBJECTIVE
  The aim of this study was to investigate potential risk factors for complications like anaemia, malabsorption or surgery in ulcerative colitis.
  
  
  METHODS
  Data on 179 patients with ulcerative colitis were retrieved from our cross-sectional and prospective Swiss Inflammatory Bowel Disease Cohort Study data base for a median observational time of 4.2 years. Data were compared between patients with (n = 140) or without (n = 39) complications. Gender, age at diagnosis, smoking status, disease extent, delay of diagnosis or therapy, mesalamine (5-ASA) systemic and topical therapy, as well as other medication were analysed as potential impact factors.
  
  
  RESULTS
  In the multivariate regression analysis a delay of 5-ASA treatment by at least two months (odds ratio (OR) 6.21 (95% confidence interval (CI) 2.13-18.14), p = 0.001) as well as a delay with other medication with thiopurines (OR 6.48 (95% CI 2.01-20.91), p = 0.002) were associated with a higher risk for complications. This significant impact of a delay of 5-ASA therapy was demonstrated for extraintestinal manifestations (EIMs) as well as extraintestinal complications (EICs). Extensive disease as well as therapy with methotrexate showed a significantly increased risk for surgery (extensive disease: OR 2.62 (1.02-6.73), p = 0.05, methotrexate: OR 5.36 (1.64-17.58), p = 0.006).
  
  
  CONCLUSIONS
  A delay of 5-ASA therapy of more than two months in the early stage of ulcerative colitis (UC) constitutes a risk for complications during disease course. Extensive disease is associated with a higher risk for surgery.
authors.affiliation: Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland; Division of Gastroenterology, See-Spital Horgen, Horgen, Switzerland.
authors.forename: Christine N
authors.initials: CN
authors.lastname: Manser
authors.affiliation: Department of Gastroenterology and Hepatology, Kantonsspital St Gallen, Switzerland.
authors.forename: Jan
authors.initials: J
authors.lastname: Borovicka
authors.affiliation: Crohn-Colitis Centre Bern-Fribourg, Switzerland.
authors.forename: Frank
authors.initials: F
authors.lastname: Seibold
authors.affiliation: Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland; Department of Gastroenterology and Hepatology, Triemlispital, Zurich, Switzerland.
authors.forename: Stephan R
authors.initials: SR
authors.lastname: Vavricka
authors.affiliation: 1st Department of Medicine, Semmelweis University, Budapest, Hungary.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Lakatos
authors.affiliation: Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Fried
authors.affiliation: Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Rogler
keywords: Ulcerative colitis; complication; extraintestinal manifestation; mesalamine; risk factor