Understanding the impact of mild traumatic brain injury on veteran service-connected disability: results from Chronic Effects of Neurotrauma Consortium.

Objectives: Disability evaluation is complex. The association between mild traumatic brain injury (mTBI) history and VA service-connected disability (SCD) ratings can have implications for disability processes in the civilian population. We examined the association of VA SCD ratings with lifetime mTBI exposure in three models: any mTBI, total mTBI number, and blast-related mTBI.Methods: Participants were 492 Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn veterans from four US VA Medical Centers enrolled in the Chronic Effects of Neurotrauma Consortium study between January 2015 and August 2016. Analyses entailed standard covariate-adjusted linear regression models, accounting for demographic, military, and health-related confounders and covariates.Results: Unadjusted and adjusted results indicated lifetime mTBI was significantly associated with increased SCD, with the largest effect observed for blast-related mTBI. Every unit increase in mTBI was associated with an increase in 3.6 points of percent SCD. However, hazardous alcohol use was associated with lower SCD.Conclusions: mTBI, especially blast related, is associated with higher VA SCD ratings, with each additional mTBI increasing percent SCD. The association of hazardous alcohol use with SCD should be investigated as it may impact veteran health services access and health outcomes. These findings have implications for civilian disability processes.