Association of Lifetime TBI and Military Employment with Late Life ADL Functioning: A Population-Based Prospective Cohort Study.

ABSTRACT

OBJECTIVE: To determine associations of traumatic brain injury (TBI) and military employment with activities of daily living (ADL) in late life. DESIGN: Population-based prospective cohort study with biennial follow-up and censoring at the time of dementia diagnosis. SETTING: Community-based integrated health care delivery system. PARTICIPANTS: Participants (N=4953) were men (n=2066) and women (n=2887) aged ≥65 years who were dementia free. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: ADL difficulties at baseline and accumulation during follow-up. RESULTS: TBI with loss of consciousness (LOC) before the age of 40 years was associated with slightly higher ADL difficulty at baseline for women (rate ratio [RR], 1.44; 95% confidence interval [CI], 1.08-1.93; P=.01). For men, TBI with LOC at any age was associated with greater ADL difficulty at baseline (age <40y RR, 1.58; 95% CI, 1.20-2.08; P=.001; age ≥40y RR, 2.14; 95% CI, 1.24-3.68; P=.006). TBI with LOC was not associated with the rate of accumulation of ADL difficulties over time in men or women. There was no evidence of an association between military employment and either outcome, nor of an interaction between military employment and TBI with LOC. Findings were consistent across a variety of sensitivity analyses. CONCLUSIONS: Further investigation into factors underlying greater late life functional impairment among survivors of TBI is warranted.