Obesity is an independent risk factor of mortality in severely injured blunt trauma patients

Hypothesis: Obesity is associated with increased morbidity and mortality in critically injured blunt trauma patients. Design: Case-control study of all critically injured blunt trauma patients between January 2002 and December 2002. Setting: Academic level I trauma center at a county referral hospital. Patients: Two hundred forty-two consecutive patients admitted to the intensive care unit following blunt trauma. Patients were divided into 2 groups by body mass index. The obese group was defined as having a body mass index of 30 kg/m² or higher, and the nonobese group was defined as having a body mass index lower than 30 kg/m². Main Outcome Measures. Univariate and multivariate analyses were performed to identify risk factors for mortality. Complications and length of stay were also evaluated. Results: Of the 242 patients, 63 (26%) were obese, and 179 (74%) were nonobese. The obese and nonobese groups were similar with regard to age (mean ± SD, 49 ± 18 years vs 45 ± 22 years), male sex (63.% vs 72%), Glasgow Coma Scale score (mean ± SD, 11 ± 5 vs 11 ± 5), and injury severity score (mean ± SD, 21 ± 13 vs 20 ± 14). The obese group had a higher body mass index (mean ± SD, 35 ± 7 vs 24 ± 3; P<.001). Mechanisms of injury and injury patterns were similar between groups. The obese group had a higher incidence of multiple organ failure (13% vs 3%; P = .02) and mortality (32% vs 16%; P = .008). Obesity was an independent predictor of mortality with an adjusted odds ratio of 5.7 (95% confidence interval, 1.9-19.6; P = .003). Conclusions: Critically injured obese trauma patients have similar demographics and injury patterns as nonobese patients. Obesity is an independent predictor of mortality following severe blunt trauma.