title: Postoperative Use of Anti-TNF-α Agents in Patients with Crohn's Disease and Risk of Reoperation-A Nationwide Cohort Study.
abstract: BACKGROUND
  Approximately 80% of patients with Crohn's disease will require surgery. Surgery for Crohn's disease is not curative, and recurrence is typical. In this cohort study, based on nationwide Danish registries, we examined the association between postoperative treatment with anti-tumor necrosis factor α (anti-TNF-α) agents and reoperation.
  
  
  METHODS
  The association was examined in cohort 1 = patients not treated with anti-TNF-α agents within 6 months before operation, cohort 2 = patients treated with anti-TNF-α agents within 6 months before operation. Within both cohorts, we defined postoperative exposure to anti-TNF-α agents as at least 1 treatment within 6 months after the first operation and the reference cohorts were those not treated. Patients were followed from 6 months after operation and until 5 years. We used Cox proportional-hazards regression to compute adjusted hazard ratios with 95% confidence intervals.
  
  
  RESULTS
  In cohort 1, 31 (1.3%) were treated with anti-TNF-α agents within 6 months after operation and compared with those not treated, the adjusted hazard ratio of reoperation among those treated with anti-TNF-α agents was 3.53 (95% confidence interval: 1.61-7.72). In cohort 2, 63 (16.3%) were treated with anti-TNF-α agents within 6 months after operation, and the corresponding adjusted hazard ratio of reoperation was 2.16 (95% confidence interval: 1.11-4.18).
  
  
  CONCLUSIONS
  Our data suggest that anti-TNF-α treatment within 6 months after the first operation is not associated with a reduction in the need for subsequent operation. Uncontrolled confounding might have influenced our results, and, furthermore, future studies are warranted to clarify whether our study population is different from populations most often associated with postoperative anti-TNF-α treatment.
authors.affiliation: *Department of Medical Gastroenterology S, Odense University Hospital, and Research Unit of Medical Gastroenterology, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark; †Center for Clinical Epidemiology, Odense University Hospital, and Research Unit of Clinical Epidemiology, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark; and ‡Department of Surgical Gastroenterology A, Odense University Hospital, and Research Unit of Surgery, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Kjeldsen
authors.forename: Jan
authors.initials: J
authors.lastname: Nielsen
authors.forename: Michael Due
authors.initials: MD
authors.lastname: Larsen
authors.forename: Niels
authors.initials: N
authors.lastname: Qvist
authors.forename: Bente Mertz
authors.initials: BM
authors.lastname: Nørgård
mesh_terms: D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D015331:Cohort Studies; D003424:Crohn Disease / Q000188:drug therapy* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D011379:Prognosis; D012086:Reoperation; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D014409:Tumor Necrosis Factor-alpha