Associations Between Combat Exposure, Traumatic Brain Injury, and Sleep Outcomes Among Post-9/11 Veterans.

OBJECTIVE: The authors examined the relationship between veterans' combat experiences and multiple dimensions of sleep health and how traumatic brain injury (TBI) history may modulate these relationships. METHODS: Participants were 17,812 post-9/11 veterans (mean±SD age=46.6±10.8; 80.1% men) enrolled in the U.S. Department of Veterans Affairs (VA) Million Veteran Program (MVP). Combat experiences were assessed with the Combat Exposure Scale (CES) from the Deployment Risk and Resilience Inventory (DRRI), with "high combat" defined as a higher frequency of all combat experiences assessed on the CES-DRRI. Sleep health variables included sleep duration, sleep disturbance, and obstructive sleep apnea (OSA) assessed via self-report on MVP surveys. Probable positive or negative TBI history was defined by using the VA TBI Clinical Reminder Screen. Group differences were evaluated with chi-square tests, t tests, analyses of variance, and regression models adjusted for demographic and clinical covariates. RESULTS: High combat exposure and screening positive for TBI were each independently and significantly associated with poorer sleep outcomes, suggesting largely additive effects of these risk factors on sleep health. Pairwise comparisons showed that veterans with high combat exposure and a positive TBI screen had the shortest sleep duration, most significant sleep disturbances, and highest OSA rates, consistent with a cumulative burden among those exposed to both risk factors. CONCLUSIONS: These findings support the notion that intensive combat exposure and probable TBI history each contributes to worse sleep health, with their combination conferring the worst outcomes. Incorporating combat exposure profiles alongside TBI screening may enhance risk stratification and support targeted, sleep-focused interventions for post-9/11 veterans.