title: The role of thiopurines in reducing the need for surgical resection in Crohn's disease: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The thiopurine (TP) analogs azathioprine and mercaptopurine have proven efficacy in inducing and maintaining clinical remission in Crohn's disease (CD). Their impact on the long-term need for surgery is uncertain since studies have reported conflicting results. The aim of this systematic review was to summarize and evaluate evidence of the published literature regarding those studies assessing the impact of TPs on the risk of first surgical resection in CD.
  
  
  METHODS
  We searched Medline, EMBASE, CINAHL, and hand searched reference lists of identified articles, without language restrictions in August 2013.
  
  
  RESULTS
  Seventeen retrospective observational studies (eight population based, three multicenter, and six referral center) representing 21,632 participants met our inclusion criteria. Of these 10 studies involving 12,586 participants provided data on the hazard ratio (HR) and 95% confidence intervals (CIs) evaluating use of TPs and surgical risk. The combined pooled HR of first intestinal resection with TP use was 0.59 (95% CI 0.48-0.73).
  
  
  CONCLUSIONS
  TP use is associated with a 40% lowered risk of surgical resection in patients with CD. Despite significant reductions in rates of surgical resection in patients with CD over the last 5 decades and increasing use of TPs, a large proportion of patients with CD still require resectional surgery.
authors: Department of Gastroenterology, St George's University Hospital, London, UK.
authors: Sukhdev
authors: S
authors: Chatu
authors: Center for Digestive Diseases, St James's University Hospital, Leeds, UK.
authors: Venkataraman
authors: V
authors: Subramanian
authors: Department of Primary Care and Public Health, Imperial College, London, UK.
authors: Sonia
authors: S
authors: Saxena
authors: Department of Gastroenterology, St George's University Hospital, London, UK.
authors: Richard C G
authors: RC
authors: Pollok
mesh_terms: D001379:Azathioprine / Q000008:administration & dosage*; D016001:Confidence Intervals; D003424:Crohn Disease / Q000188:drug therapy / Q000453:epidemiology / Q000601:surgery; D013505:Digestive System Surgical Procedures / Q000706:statistics & numerical data*; D019468:Disease Management; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D015122:Mercaptopurine / Q000008:administration & dosage*; D064887:Observational Studies as Topic; D059351:Organ Sparing Treatments / Q000379:methods; D017063:Outcome Assessment, Health Care; D016016:Proportional Hazards Models; D012074:Remission Induction / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment
chemical_list: D007166:Immunosuppressive Agents; D015122:Mercaptopurine; D001379:Azathioprine