Stroke risk and outcomes in patients with traumatic brain injury: 2 Nationwide studies

Objective: To investigate whether patients with traumatic brain injury (TBI) have an increased risk of stroke or poststroke mortality. Participants and Methods: Using Taiwan's National Health Insurance Research Database, we conducted a retrospective cohort study of 30,165 patients with new TBI and 120,660 persons without TBI between January 1, 2000, and December 31, 2004. The risk of stroke was compared between 2 cohorts through December 31, 2008. To investigate the association between in-hospital mortality after stroke and history of TBI, we conducted a casecontrol study of 7751 patients with newly diagnosed stroke between January 1, 2005, and December 31, 2008. Results: The TBI cohort had an increased stroke risk (hazard ratio [HR], 1.98; 95% CI, 1.86-2.11). Among patients with stroke, those with a history of TBI had a higher risk of poststroke mortality compared with those without TBI (odds ratio, 1.57; 95% CI, 1.13-2.19). In the TBI cohort, factors associated with stroke were history of TBI hospitalization (HR, 3.14; 95% CI, 2.77-3.56), emergency care for TBI (HR, 3.37; 95% CI, 2.88-3.95), brain hemorrhage (HR, 2.69; 95% CI, 2.43-2.99), skull fracture (HR, 3.00; 95% CI, 2.42-3.71), low income (HR, 2.65; 95% CI, 2.16-3.25), and high medical expenditure for TBI care (HR, 2.26; 95% CI, 2.09-2.43). The severity of TBI was also correlated with poststroke mortality. Conclusions: Traumatic brain injury was associated with risk of stroke and poststroke mortality. The relationship between TBI and poststroke mortality does not seem to transcend all age groups. This research shows the importance of prevention, early recognition, and treatment of stroke in this vulnerable population.