Background: One third of US adults are obese. The impact of obesity on outcomes after blunt traumatic injury has been studied with discrepant results. The aim of our study was to evaluate outcomes in morbidly obese patients after blunt trauma. We hypothesized that morbidly obese patients have adverse outcomes as compared with nonobese patients after blunt traumatic injury.
Methods: We performed a retrospective analysis of all blunt trauma patients (≥18 years) using the National Trauma Data Bank for years 2007 to 2010. Patients with recorded comorbidity of morbid obesity (body mass index ≥ 40) were identified. Patients transferred, dead on arrival, and with isolated traumatic brain injury were excluded. Propensity score matching was used to match morbidly obese patients to non-morbidly obese patients (body mass index < 40) in a 1:1 ratio based on age, sex, Injury Severity Score (ISS), Glasgow Coma Scale (GCS), and systolic blood pressure on presentation. The primary outcome was mortality, and the secondary outcome was hospital complications.
Results: A total of 32,780 patients (morbidly obese, 16,390; nonobese, 16,390) were included in the study. Morbidly obese patients were more likely to have in-hospital complications (odds ratio [OR], 1.8, 95% confidence interval [CI], 1.6-1.9), longer hospital stay (OR, 1.2; 95% CI, 1.1-1.3), and longer intensive care unit stay (OR, 1.15; 95% CI, 1.09-1.2). The overall mortality rate was 2.8% (n = 851). Mortality was higher in morbidly obese patients compared with the nonobese patients (3.0 vs. 2.2; OR, 1.4; 95% CI, 1.1-1.5).
Conclusion: In a cohort of matched patients, morbid obesity is a risk factor for the development of in-hospital complications and mortality after blunt traumatic injury. The results of our study call for attention through focused injury prevention efforts. Future studies are needed to help define the consequences of obesity that influence outcomes.
Level of evidence: Prognostic study, level III.