6-Month Recovery after Mild Traumatic Brain Injury in Older Adults: A TRACK-GERI Study.

Importance: Older adults (≥65 years old) are the largest and fastest growing population of traumatic brain injury (TBI) victims. However, real-world evidence of 6-month functional outcomes is limited. Objective: To describe 6-month functional outcomes in older adults after mild TBI (mTBI; presenting Glasgow Coma Scale score 13-15), by age group and preinjury cognitive status. To evaluate the performance of the Glasgow Outcome Scale-Extended (GOSE) as a geriatric mTBI clinical trial endpoint. Design: Prospective cohort study; single-center pilot enrollment February 2018-April 2019; two-center enrollment October 2020-March 2025. Setting: Two U.S. level I trauma centers. Participants: Older adults presenting within 72 hours of mTBI who received head CT, and their co-enrolled study-partner informants. Data curation and analysis were performed January 2023-November 2025. Exposure: mTBI. Main outcome and measures: GOSE was assessed at 2 weeks and 6 months post-injury and weighted using inverse probability weighting to mitigate attrition bias. Reliable change index was used to estimate the proportions of GOSE improvement or deterioration from 2 weeks to 6 months versus a 9-item Activities of Daily Living survey (ADL, Supplemental Methods) and Functional Activities Questionnaire (FAQ). Results: Among 253 participants with mTBI, mean (SD) age was 77.3 (8.3) years, 129 (51%) were female, 68 (34%) had pre-injury mild cognitive impairment and 28 (15%) had pre-injury dementia (58 had unknown preinjury cognitive status). At 6 months, 14% died, 73% achieved home independence (GOSE 5+), and 17% achieved complete recovery (GOSE 8). Younger-old and persons without preinjury cognitive impairment had substantially better recovery (mortality 6-11%, home independence 84-86%, complete recovery 21-22%) versus oldest-old and those with pre-injury dementia (mortality 29-32%, home independence 23-52%, complete recovery 5-10%). GOSE detected the greatest proportion of reliable improvement or deterioration compared to ADL and FAQ, though low agreement reflects their complementary domains. Conclusions and Relevance: Most younger and cognitively-unimpaired older adults achieved favorable functional outcomes, however, more vulnerable older adults may suffer chronic disability after mTBI. GOSE effectively captures meaningful change in this population, while ADL and FAQ provide important complementary information. Findings underscore the need for age-appropriate prognostication and more inclusive geriatric TBI research and clinical trial design. Trial Registration: NCT07296783.