Post-Discharge Mortality of Older Adults with Traumatic Brain Injury or Other Trauma

OBJECTIVES Prior studies of mortality following traumatic brain injury (TBI) have not focused specifically on older adults compared with a non-TBI trauma cohort or included specific causes of death. The objectives of this study were, among adults aged 65 years and older, to (1) generate standardized mortality ratios (SMRs) by cause of death for TBI and a non-TBI trauma cohort compared with a general population, and (2) assess risk of mortality associated with TBI compared with a non-TBI trauma cohort. DESIGN Retrospective cohort study of adults aged 65 years and older who were treated at an urban trauma center from 1997 to 2008. MEASUREMENTS Data from the trauma registry were linked to the National Death Index through 2008 to obtain date and cause of death. We identified individuals with TBI and non-TBI trauma and calculated age- and sex-adjusted SMRs by comparing with the state general population. We next compared time to mortality between individuals with TBI (n = 852) and non-TBI trauma (n = 1050), adjusting for potential confounders. RESULTS Compared with the age- and sex-adjusted state general population, older adults with TBI (SMR = 8.1; 95% confidence interval [CI] = 7.4-9.0) and non-TBI trauma (SMR = 6.7; 95% CI = 6.1-7.4) were at a greatly increased risk of mortality. Highest SMRs in both cohorts were observed for accidents. In adjusted Cox regression models, TBI was not associated with increased risk of all-cause mortality (hazard ratio = 1.03; 95% CI = .87-1.23) compared with non-TBI trauma. CONCLUSION This study provides evidence that, over a 4-year follow-up of older adults, any moderate to severe injury is associated with increased mortality risk. Specifically, older injured adults are at high risk of death from accidental and therefore preventable causes, suggesting that intervention could reduce mortality.