title: The long-term risk of venous thromboembolism following bariatric surgery.
abstract: BACKGROUND
  Venous thromboembolism (VTE) is a leading cause of morbidity and mortality following bariatric surgery. The exact duration and magnitude of post-surgery risk for VTE, however, is unclear. We analyzed a large administrative database to determine the long-term risk and predictors for VTE in patients undergoing bariatric surgery.
  
  
  METHODS
  A private insurance claims database was used to identify 17,434 patients who underwent bariatric surgery. Longitudinal data were available for each patient for up to 12 months post-surgery. We used logistic regression to identify independent predictors for VTE events.
  
  
  RESULTS
  The incidence of VTE during the index surgical hospitalization was .88%. This cumulative rate rose to 2.17% at 1 month and 2.99% by 6 months post-surgery. Over 74% of VTE events occurred after discharge. Risk factors identified for VTE developing by 6 months post-surgery included male sex (odds ratio (OR) = 1.68; confidence limits (CL) = 1.37-2.07), age ≥ 55 years (OR = 2.18; CL = 1.56-3.03), smoking (OR = 1.86; CL = 1.06-3.27), and previous VTE (OR = 7.48; CL = 5.78-9.67). The laparoscopic adjustable gastric band was less likely to result in VTE compared to open or laparoscopic gastric bypass (OR = .31; CL = .13-.75).
  
  
  CONCLUSIONS
  The period of increased risk for VTE following bariatric surgery extends well beyond the initial hospital discharge and 30 days after surgery. The high frequency of VTE up to 6 months following bariatric surgery suggests that more aggressively extended prophylaxis should be considered in patients at higher risk for VTE.
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA. ksteele3@jhmi.edu
authors.forename: Kimberley Eden
authors.initials: KE
authors.lastname: Steele
authors.forename: Michael A
authors.initials: MA
authors.lastname: Schweitzer
authors.forename: Gregory
authors.initials: G
authors.lastname: Prokopowicz
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Shore
authors.forename: Lisa C B
authors.initials: LC
authors.lastname: Eaton
authors.forename: Anne O
authors.initials: AO
authors.lastname: Lidor
authors.forename: Martin A
authors.initials: MA
authors.lastname: Makary
authors.forename: Jeanne
authors.initials: J
authors.lastname: Clark
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Magnuson
mesh_terms: D000328:Adult; D000367:Age Factors; D050110:Bariatric Surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D009767:Obesity, Morbid / Q000150:complications / Q000601:surgery*; D016017:Odds Ratio; D011183:Postoperative Complications / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D054556:Venous Thromboembolism / Q000453:epidemiology / Q000209:etiology*