title: Risk factors for post-operative mortality in bariatric surgery.
abstract: BACKGROUND
  Appropriate patient selection is crucial to the success of bariatric surgery (BaS). The objective of this study was to identify risk factors for increased post-operative mortality in patients undergoing BaS using a nationally representative sample.
  
  
  METHODS
  BaS patients > or = 18 years old in the United States were identified from the 2001 Nationwide Inpatient Sample (NIS). The effect of gender, age, insurance status, and need for re-operation on post-operative mortality was examined using a multivariate logistic regression model.
  
  
  RESULTS
  A national cohort of 54,878 patients was identified with age 41 +/- 0.2 years (mean +/- SE), 84% women, length of stay (LOS) 3.9 +/- 0.2 days, and overall mortality of 4 per 1,000 BaS patients. Mean LOS of those who died was 17.6 +/- 3.7 days. Adjusting for comorbidities and demographics, men had increased likelihood of death [odds ratio (OR) 2.1, 95% confidence interval (CI) 1.1-4.3, P < 0.05]. Compared to younger patients, those aged above 39 years had over two-fold risk of death [ages 40-49: OR 2.6, 95% CI 1.1-6.5, P < 0.05; ages 50-59: OR 4.3, 95% CI 1.7-11, P < 0.05]. Medicaid patients [OR 4.7, 95% CI 1.2-13, P < 0.05 compared to privately insured] and those requiring re-operation [OR 22, 95% CI 5.4-88, P < 0.05] had higher odds of dying.
  
  
  CONCLUSIONS
  Based on national data, risk factors for increased post-operative mortality in BaS patients include male gender, age > 39 years, Medicaid insured, and need for re-operation. These data can assist in optimizing BaS patient outcomes.
authors.affiliation: Division of General Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA. benjamin.poulose@vanderbilt.edu
authors.forename: Benjamin K
authors.initials: BK
authors.lastname: Poulose
authors.forename: Marie R
authors.initials: MR
authors.lastname: Griffin
authors.forename: Derek E
authors.initials: DE
authors.lastname: Moore
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Zhu
authors.forename: Walter
authors.initials: W
authors.lastname: Smalley
authors.forename: William O
authors.initials: WO
authors.lastname: Richards
authors.forename: J Kelly
authors.initials: JK
authors.lastname: Wright
authors.forename: Willie
authors.initials: W
authors.lastname: Melvin
authors.forename: Michael D
authors.initials: MD
authors.lastname: Holzman
mesh_terms: D000328:Adult; D049088:Bariatrics; D015331:Cohort Studies; D005260:Female; D015390:Gastric Bypass / Q000009:adverse effects; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000601:surgery*; D011183:Postoperative Complications / Q000401:mortality*; D012307:Risk Factors; D013514:Surgical Procedures, Operative / Q000009:adverse effects*; D014481:United States