Purpose Following combat deployments, veterans have an increased risk of fatal motor vehicle crash (MVC) than civilians or non-combat veterans. Risk of nonfatal MVC also appears to be elevated. Little research has examined health-related risk factors for MVC in this population.

Methods Department of Veterans Affairs (VA) data were used to identify a cohort of n=27 134 post-9/11 combat veterans residing in Oregon for any length of time between October 2001 and June 2015. This file was probabilistically linked to Department of Motor Vehicles (DMV) data identifying MVCs in the state of Oregon during this same time-period. Cox-proportional hazard models were used to examine associations between veterans’ VA healthcare diagnoses and risk of MVC. Diagnoses of interest were those that are relatively frequent among post-deployment veterans and hypothesised to affect MVC risk; these included post-traumatic stress disorder (PTSD), traumatic brain injury, depression, anxiety, substance use disorders, and sensory deficits. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated while adjusting for age, gender, race, marital status, and education.

Results We identified 2242 (8.3%) veterans involved in MVCs during the study period. Veterans with diagnoses of PTSD (HR=1.2; 95% CI: 1.0–1.3) and alcohol use disorder (HR=1.3; 95% CI: 1.0–1.3) were more likely to be involved in a MVC compared to Veterans without the respective diagnoses. Other diagnoses examined were not associated with risk of MVC.

Conclusion Select post-deployment health diagnoses appeared to be associated with risk of MVC among post-9/11 combat Veterans.

Significance Approximately 2.7 million post-9/11 military service members have been deployed to combat zones in and around Iraq and Afghanistan. Prevention efforts targeting those at greatest risk for post-deployment MVC may prevent fatal and nonfatal injury in this population. Potential interventions include screening and referral to mental and behavioural health services.