Deployment experiences and motor vehicle crashes among U.S. service members.

BACKGROUND Motor vehicle crashes (MVCs) continue to account for a third of service member fatalities each year. Sociodemographic factors associated with MVCs among service members have been evaluated, but whether deployment-specific experiences during the recent operations are associated with a higher risk of MVCs is unclear. PURPOSE Evaluate if military members with specific deployment experiences are at an increased risk of MVCs, while taking into account several potential confounders. METHODS Millennium Cohort Study participants who enrolled during 2001-2006 and were on active-duty service were evaluated. The Military Health System Data Repository (MDR) was used to investigate MVC-related injuries occurring 6 months postdeployment in relation to service-related factors, while adjusting for demographic, behavioral, and mental and physical health factors. Analysis conducted in 2012 used Cox proportional hazards modeling. RESULTS There were 13,620 deployed personnel included in this study. After adjusting for covariates, deployers with combat experiences (hazard ratio [HR]=1.86, 95% CI=1.33, 2.62) and those with more than one deployment (two deployments, HR=1.93, 95% CI=1.32, 2.83; three or more deployments, HR=2.83, 95% CI=1.71, 4.67) had an increased risk for an MVC within 6 months postdeployment. Enlisted rank and non-Hispanic black race/ethnicity were also associated with increased risk for MVCs. CONCLUSION Experiencing combat during deployment and multiple deployments are both strong predictors for MVCs within 6 months of returning home among U.S. military members. These data provide critical information for targeting prevention strategies to decrease MVCs among personnel postdeployment.