Risk factors for post-operative mortality in bariatric surgery.

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.

MATERIALS AND 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.

CONCLUSION: 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.