Racial/ethnic differences in combat- and non-combat-associated traumatic brain injury severity in the Veterans Health Administration: 2004-2010

Objectives. We examined the association between traumatic brain injury (TBI) severity and combat exposure by race/ethnicity. Methods. We estimated logit models of the fully adjusted association of combat exposure with TBI severity in separate race/ethnicity models for a national cohort of 132 995 veterans with TBI between 2004 and 2010. Results. Of veterans with TBI, 25.8% had served in a combat zone. Mild TBI increased from 11.5% to 40.3%, whereas moderate or severe TBI decreased from 88.5% to 59.7%. Moderate or severe TBI was higher in non-Hispanic Blacks (80.0%) and Hispanics (89.4%) than in non-Hispanic Whites (71.9%). In the fully adjusted all-race/ethnicity model, non-Hispanic Blacks (1.44; 95% confidence interval [CI] = 1.37, 1.52) and Hispanics (1.47; 95% CI = 1.26, 1.72) had higher odds of moderate or severe TBI than did non-Hispanic Whites. However, combat exposure was associated with higher odds of mild TBI in non-Hispanic Blacks (2.48; 95% CI = 2.22, 2.76) and Hispanics (3.42; 95% CI = 1.84, 6.35) than in non-Hispanic Whites (2.17; 95% CI = 2.09, 2.26). Conclusions. Research is needed to understand racial differences in the effect of combat exposure on mild TBI and on interventions to prevent TBI across severity levels.