J. J. Ray1, S. S. Satahoo1, C. J. Allen1, J. P. Meizoso1, C. M. Thorson1, L. F. Teisch1, J. E. Sola2, K. G. Proctor1, L. R. Pizano1, N. Namias1, C. I. Schulman1 1University Of Miami,Divisions of Trauma, Surgical Critical Care, and Burns,Miami, FL, USA 2University Of Miami,Division of Pediatric and Adolescent Surgery,Miami, FL, USA
Introduction: It is recognized that negative outcomes are associated with obesity in trauma, but less is known about outcomes in burn patients. We aim to bridge this gap to better understand the association of obesity to clinical and economic outcomes in the burn population. We hypothesize that obesity is an independent predictor of adverse events.
Methods: The National Inpatient Sample was queried for adult patients (age ≥ 18 years) with an “emergency,” “urgent,” or “trauma center” admission from 2005-2009, and ICD-9 codes for burn injury. Patients with isolated injuries to the internal organs and eyes (941-946.5, 948-949.5) were excluded as were those with missing data for total body surface area (TBSA) burn and/or burn degree. Demographics, disease severity, length of stay (LOS), discharge disposition, hospital costs and outcomes were reviewed. Parametric data are represented as mean±standard deviation and non-parametric data as median(interquartile range). Univariate and multivariate analysis logistic regression models were performed.
Results: In 14,602 patients, 3.3% were obese (body mass index>30). The rate of obesity increased significantly over the study period (2005: 1.7%, 2006: 2.0%, 2007: 2.8%, 2008: 4.6%, 2009: 5.2%, p<0.001). On univariate analysis, there were no significant differences between obese and non-obese patients in terms of race, TBSA burn, degree of burn, need for mechanical ventilation, or household income. Significant differences were noted in incidence of wound infection (7.2%vs5.0%), urinary tract infection (UTI) (7.2%vs4.6%), deep vein thrombosis (DVT) in TBSA burn ≥ 10% (3.1 vs 1.1%), pulmonary embolism (PE) in TBSA burn ≥ 10% (2.3%vs0.6%), discharge to home (57.7%vs66.6%), high disease severity (91.8%vs73.5%), LOS [6(8) vs 5(9)] and hospital costs [$10,122.12($19,825.21) vs $7892.07($17.191.96)] (all p <0.05). Significant predictors of adverse events (UTI, wound infection, DVT, or PE) included: obesity (15.2%vs10.1%), TBSA ≥ 20% (14.6%vs9.6%), age (53±20y vs 45±18y) and black race (13.0%vs9.9%). These remained significant on multivariate analysis using a logistic regression model (area under receiver operator curve= 0.703) (Table).
Conclusion: In burn patients, obesity is an independent predictor of adverse events along with TBSA ≥ 20, age, and black race. Our findings highlight the potential clinical and economic impact of the obesity epidemic on burn patients nationwide.
