Predictive factors of mortality in bariatric surgery: Data from the Nationwide Inpatient Sample Ninh T. Nguyen, MD, Hossein Masoomi, MD, Kelly Laugenour, BS, Yas Sanaiha, BS, Kevin M. Reavis, MD, Steven D. Mills, MD, and Michael J. Stamos, MD, Orange, CA Background. Understanding predictors of mortality in bariatric surgery enables surgeons to use these factors for analysis of risk-adjusted mortality and aids in the surgical decision making and informed consent process. Objectives. To evaluate the effect of patient characteristics (age, gender, race, and payer type), preoperative comorbidities, and operative technique (laparoscopic versus open, gastric bypass versus gastric band) on mortality in patients who underwent bariatric operations. Methods. Using the National Inpatient Sample database, clinical data of patients with morbid obesity who underwent bariatric surgery from 2006 to 2008 were examined. Multivariate logistic regression analyses were performed to identify independent predictors of in-hospital mortality. Results. A total 304,515 patients underwent bariatric surgery over the 3-year period. The majority of patients were female (80%) and Caucasian (74%). Their mean age was 44 years and 31.6% were >50 years old. The most common payer type was private (73.5%). Laparoscopic approach was utilized in 86.2% of cases. The overall in-hospital mortality was 0.12%. Using multivariate regression analysis, male gender (adjusted odds ratio [AOR], 1.7), age >50 years (AOR, 3.8), congestive heart failure (AOR, 9.5), peripheral vascular disease (AOR, 7.4), chronic renal failure (AOR, 2.7), open procedure (AOR, 5.5), and gastric bypass operation (AOR, 1.6) were factors associated with greater mortality. Ethnicity, hypertension, diabetes, liver disease, chronic lung disease, sleep apnea, alcohol abuse, and payer type had no association with mortality in this study. Conclusion. Modifiable risk factors predictive of mortality include open surgery and gastric bypass procedure; nonmodifiable risk factors include older age, male gender, and a history of congestive heart failure, peripheral vascular disease, and chronic renal failure. Surgeons should consider these factors in selection of patients to undergo bariatric operations, providing informed consent, and selection of the procedural type. (Surgery 2011;150:347-51.) From the Department of Surgery, University of California, Irvine Medical Center, Orange, CA PATIENTS WITH SEVERE OBESITY OFTEN have multiple co- morbid conditions, such as type 2 diabetes mellitus, hypertension, coronary artery disease, obesity– hypoventilation syndrome, and obstructive sleep ap- nea, that increase their risk for mortality. 1 Bariatric surgery has been shown to improve or resolve many of these obesity-related comorbidities, and several recent controlled studies have shown that long- term mortality is improved after bariatric surgery. 2-4 Although the benefits of bariatric surgery are well- documented, the issue of safety in bariatric surgery continues to be a major hurdle for patients and primary care providers. Some patients are reluctant to undergo bariatric surgery, and primary care pro- viders are reluctant to refer their patients for bariatric surgery because of the inherent risks. Outcomes of bariatric surgery have improved dramatically over the past decade with the introduction of the laparo- scopic approach, the increasing volume of bariatric surgery, formal fellowship training programs, and the emergence of center of excellence programs. 5 Between 1998 and 2002, the number of bariatric op- eration increased from 12,775 procedures to 70,256 procedures and the in-hospital mortality decreased from 0.8% to 0.5%. 5 Between 2004 and 2007, mortal- ity for laparoscopic gastric bypass decreased to 0.1%. 6 In a continued effort to improve safety in bariatric surgery, it is important to understanding Presented at the Academic Surgical Congress on February 2, 2011, Huntington Beach, CA. Accepted for publication May 16, 2011. Reprint requests: Ninh T. Nguyen, MD, Department of Surgery, 333 City Building West, Suite 850, Orange, CA 92868. E-mail: ninhn@uci.edu. 0039-6060/$ - see front matter Ó 2011 Mosby, Inc. All rights reserved. doi:10.1016/j.surg.2011.05.020 SURGERY 347