Background: This study investigates the influence of overweight and obesity on outcome from vehicular trauma.
Methods: All Crash Injury Research and Engineering Network patients older than 16 years involved in frontal and lateral crashes between 2000 and 2005 in vehicles with front airbags were included (n = 1,615). Obese, overweight, and normal-weight patients were compared in relation to injury severity score (ISS) and mortality using the Bonferroni method for multiple comparisons and the chi test. Control variables included patient factors (gender, age, and height) and crash factors (curb weight, change in velocity [DeltaV], principal direction of force, and restraint use). Multivariate analysis was performed for both ISS and mortality using linear and logistic regression, respectively. An alpha value of 0.05 was used for all statistics.
Results: Univariate analysis showed no difference in ISSs between groups based on body mass index. Mortality was higher for obese and overweight than for normal-weight patients (20.5%, 16.2%, and 9.4%, respectively). Multiple linear regression revealed a positive association of ISS with overweight (parameter estimate 2.44, p = 0.009) but not with obese patients. Crash factor adjusted odds of dying were 2.08 (CI 1.43-3.04) for overweight and 3.17 (CI 2.14-4.72) for obese patients. Injury-severity-adjusted odds of dying were 1.87 (CI 1.17-3.01) for overweight and 3.89 (CI 2.38-6.45) for obese patients.
Conclusion: After adjusting for age, gender, and crash factors, overweight patients (but not obese patients) experienced more severe injuries. Obese and overweight patients experience higher unadjusted and adjusted mortality rates.