Impact of age on long-term recovery from traumatic brain injury.

OBJECTIVE: To determine whether older persons are at increased risk for progressive functional decline after traumatic brain injury (TBI). DESIGN: Longitudinal cohort study. SETTING: Traumatic Brain Injury Model Systems (TBIMS) rehabilitation centers. PARTICIPANTS: Subjects enrolled in the TBIMS national dataset. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Disability Rating Scale (DRS), FIM instrument cognitive items, and the Glasgow Outcome Scale-Extended. RESULTS: Participants were separated into 3 age tertiles: youngest (16-26y), intermediate (27-39y), and oldest (> or =40y). DRS scores were comparable across age groups at admission to a rehabilitation center. The oldest group was slightly more disabled at discharge from rehabilitation despite having less severe acute injury severity than the younger groups. Although DRS scores for the 2 younger groups improved significantly from year 1 to year 5, the greatest magnitude of improvement in disability was seen among the youngest group. In addition, after dividing patients into groups according to whether their DRS scores improved (13%), declined (10%), or remained stable (77%) over time, the likelihood of decline was found to be greater for the 2 older groups than for the youngest group. A multiple regression model showed that age has a significant negative influence on DRS score 5 years post-TBI after accounting for the effects of covariates. CONCLUSIONS: This study supported our primary hypothesis that older patients show greater decline over the first 5 years after TBI than younger patients. In addition, the greatest amount of improvement in disability was observed among the youngest group of survivors. These results suggest that TBI survivors, especially older patients, may be candidates for neuroprotective therapies after TBI.