Abstract
Objective: Risk of ischemic stroke and depression is elevated among older adults following traumatic brain injury (TBI), yet little is known about how the severity of TBI influences risk. Thus, our objective was to assess the association between severity of the index TBI and risk of ischemic stroke and depression in a sample of older adults treated for TBI.
Design: Retrospective cohort study.
Setting: R Adams Cowley Shock Trauma Center.
Participants: Adults 65 years and older treated for TBI between 2006 and 2010 who survived to hospital discharge and could be linked to their Medicare administrative claims data with continuous enrollment for at least 6 months pre-TBI and 12 months post-TBI.
Main Measures: First dates of ischemic stroke and depression available in Medicare claims were used to exclude individuals with a history. Next, we separately assessed the association between TBI severity and time to first stroke and depression using Cox proportional hazards models.
Results: Among 132 patients without preexisting history of stroke, high TBI severity was associated with increased risk of stroke compared with low TBI severity (adjusted hazard ratio 6.68, 95% confidence interval 2.49-17.94). Among 163 patients without preexisting history of depression, high TBI severity was not significantly associated with increased risk of depression compared with low TBI severity (adjusted hazard ratio 1.90, 95% confidence interval 0.94-3.84).
Conclusion: In this group of older adults with TBI, higher TBI severity was associated with increased risk of ischemic stroke, but not depression. These results suggest that increased monitoring of older adults with moderate-severe TBI for stroke may be warranted.