Associations Between Traumatic Brain Injury History and Future Headache Severity in Veterans: A Longitudinal Study

Abstract Objective To determine whether traumatic brain injury (TBI) history is associated with worse headache severity outcomes. Design Prospective cohort study. Setting Department of Veterans Affairs (VA) outpatient clinics. Participants Veterans (N=2566) who completed a mail follow-up survey an average of 3 years after a comprehensive TBI evaluation (CTBIE). Interventions Not applicable. Main Outcome Measures The presence or absence of TBI, and TBI severity were evaluated by a trained clinician and classified according to VA/Department of Defense clinical practice guidelines. Headache severity was evaluated at both the baseline CTBIE assessment and 3-year follow-up using a 5-level headache score ranging from 0 ("none") to 4 ("very severe") based on headache-associated activity interference in the past 30 days. We examined associations of mild and moderate/severe TBI history, as compared to no TBI history, with headache severity in cross-sectional and longitudinal analyses, with and without adjustment for potential confounders. Results Mean headache severity scores were 2.4 at baseline and 2.3 at 3-year follow-up. Mild TBI was associated with greater headache severity in multivariate-adjusted cross-sectional analyses (β [SE]=.61 [.07], P P =.20). Moderate/severe TBI was significantly associated with greater headache severity in both cross-sectional (β [SE]=.66 [.09], P P =.04). Conclusions Headache outcomes are poor in veterans who receive VA TBI evaluations, irrespective of past TBI exposure, but significantly worse in those with a history of moderate/severe TBI. No association was found between mild TBI and future headache severity in veterans. Veterans with headache presenting for TBI evaluations, and particularly those with moderate/severe TBI, may benefit from further evaluation and treatment of headache.