title: Impact of azathioprine and tumour necrosis factor antagonists on the need for surgery in newly diagnosed Crohn's disease.
abstract: OBJECTIVE
  The aim of the study was to assess whether azathioprine and antitumour necrosis factor (TNF) treatment decrease the long-term need for surgery in patients with Crohn's disease.
  
  
  METHODS
  This was an observational study of a referral centre cohort. The cumulative incidence of the first Crohn's disease-related major abdominal surgery was estimated using the Kaplan-Meier method, and independent predictors of surgery were identified using Cox proportional hazards regression with propensity scores adjustment. Receiver operating characteristic (ROC) analysis was used to identify optimal cut-offs for duration of maintenance treatments. The electronic charts of 296 incident cases of Crohn's disease from Nancy University Hospital, France, diagnosed between 2000 and 2008, were reviewed through January 2010.
  
  
  RESULTS
  The median follow-up time per patient was 57 months. Seventy-six patients (26%) underwent at least one major abdominal surgical procedure. The cumulative probabilities of the first Crohn's disease-related major abdominal surgery were 6.5, 25.9 and 44.3 at 1, 5 and 9 years, respectively. In the ROC analysis, the duration of anti-TNF and azathioprine treatment had significant cut-off values (≤ 475 days ~16 months and ≤ 45 days ~1.5 months, respectively) with positive likelihood ratios (PLRs) of 1.52 (p < 0.0001) and 1.51 (p = 0.003) for the first Crohn's disease-related major abdominal surgery. Using multivariate Cox proportional hazards regression analysis (after propensity score adjustment), independent positive predictors of major abdominal surgery were stricturing (HR = 12.01; 95% CI 5.97 to 24.17) or penetrating (HR = 10.77; 95% CI 4.87 to 23.80) disease behaviour at diagnosis, duration of anti-TNF treatment of < 16 months (HR = 3.86; 95% CI 1.77 to 8.45) and duration of azathioprine treatment of < 1.5 months (HR = 2.00; 95% CI 1.20 to 3.34).
  
  
  CONCLUSIONS
  Non-complicated inflammatory disease behaviour and long-term anti-TNF treatment are associated with a lower risk for surgery whereas azathioprine only modestly lowers this risk.
authors.affiliation: Department of Hepato-Gastroenterology, University Hospital of Nancy-Brabois, Vandoeuvre-lès-Nancy, France. peyrinbiroulet@gmail.com
authors.forename: Laurent
authors.initials: L
authors.lastname: Peyrin-Biroulet
authors.forename: Abderrahim
authors.initials: A
authors.lastname: Oussalah
authors.forename: Nicolas
authors.initials: N
authors.lastname: Williet
authors.forename: Claire
authors.initials: C
authors.lastname: Pillot
authors.forename: Laurent
authors.initials: L
authors.lastname: Bresler
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Bigard
mesh_terms: D000293:Adolescent; D000328:Adult; D001379:Azathioprine / Q000008:administration & dosage / Q000627:therapeutic use*; D003131:Combined Modality Therapy / Q000379:methods; D003424:Crohn Disease / Q000188:drug therapy* / Q000601:surgery; D004334:Drug Administration Schedule; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*; D055815:Young Adult
chemical_list: D007166:Immunosuppressive Agents; D014409:Tumor Necrosis Factor-alpha; D001379:Azathioprine