Health Problems Precede Traumatic Brain Injury in Older Adults

Objectives To evaluate whether indices of preinjury health and functioning are associated with risk of incident traumatic brain injury (TBI) with loss of consciousness (LOC) and to evaluate health-related factors associated with mortality in individuals with incident TBI. Design Prospective community cohort study. Setting Group Health, Seattle, Washington. Participants Individuals aged 65 and older with no self-reported prior TBI with LOC (N = 3,363) were enrolled and followed every 2 years for an average of 7.5 years (range 0-18 years). Measurements Weibull survival models were used to evaluate baseline and time-varying predictors of incident TBI with LOC, including measures of depression, activities of daily living (ADLs), cerebrovascular disease, and disease comorbidity. Results In an adjusted multivariate model, baseline depression symptoms as measured according to Center for Epidemiologic Studies Depression Scale (CES-D) score (hazard ratio (HR) for 4 points = 1.23, 95% confidence interval (CI) = 1.02-1.49, P =.03) and baseline activity of daily living (ADL) impairment (HR = 2.37, 95% CI = 1.24-4.53, P =.009) were associated with incident TBI. In a model that included time-dependent covariates, cerebrovascular disease at the previous visit (HR = 2.28, 95% CI = 1.37-3.78, P <.001), CES-D score the previous visit (HR for 4 points = 1.23, 95% CI = 1.02-1.49, P <.04) and baseline ADL impairment (HR 2.14, 95% CI = 1.11-4.13, P =.02) predicted incident TBI. Of factors considered, cerebrovascular disease and ADL impairment were associated with earlier mortality in participants with incident TBI with LOC. Conclusion Indices of health, mood, and functional status predict incident TBI with LOC in older adults. These findings may have implications for injury prevention and postinjury clinical management.