Concussion recovery trajectories among United States Service Academy Members

Abstract

PURPOSE: Describe concussion/mild traumatic brain injury (mTBI) recovery durations by sex and injury-related activities in US Service Academy cadets. METHODS: Injury data (2014-2017) from three US Military Service Academies were examined to describe concussion/mTBI characteristics (n=800 injuries, 301 female). Of the documented injuries, there were 738 injured individuals, of which, 679 had one injury, 56 individuals had two injuries and three individuals had three injuries. The recovery trajectories for all injuries were examined across sex and injury activity. Three durations were examined: days until asymptomatic, duration of return to activity (RTA) protocol, and days of total time lost. Duration was examined using Kaplan-Meier and log-rank tests. Due to the right skewed distribution, medians and interquartile range (IQR) are reported. RESULTS: Across all cadets, the median days until asymptomatic was 9 (IQR: 5-16). The median duration of RTA protocol was 5 days (IQR: 5-7). The total time lost due to concussion/mTBI was 20.68 days (IQR: 12.78-33.12). There was a significant effect of sex for days until asymptomatic and total time lost (p’s < 0.01). Across all recovery metrics, females were more likely to have more days until asymptomatic (11 vs. 8.0 median days) and total time lost (24.6 vs 18.8 days). A significant effect of injury activity was observed for days until asymptomatic and total time lost (p’s < 0.05). Injuries occurring during free-time activities had the greatest median number of days until asymptomatic (13 days IQR: 10-15) while injuries occurring during varsity athletics or academy specific training had the fewest median days until asymptomatic (both 6 days). Injuries occurring during varsity athletics had the shortest median total time loss of 12.9 days (IQR: 11.95-15.73). All other injury mechanisms were associated with median time loss of more than 20 days. CONCLUSIONS: These analyses show significant effects of sex and injury activity on recovery duration. Differences may also reflect varying approaches to injury management by the medical provider. Further investigation is needed to determine an individualized approach to clinical care.