Clinical Measures Associated with Subsequent Injury after Adolescent Concussion: A Prospective Cohort Study.

PURPOSE

This study aimed to examine associations between clinical measures (self-reported and clinician administered) and subsequent injury rates in the year after concussion return to play (RTP) among adolescent athletes.

METHODS

We performed a prospective, longitudinal study of adolescents ages 13-18 yr. Each participant was initially assessed within 21 d of concussion and again within 5 d of receiving RTP clearance from their physician. Participants completed self-report measures: the Pittsburgh Sleep Quality Index and Tampa Scale of Kinesiophobia, and clinician-administered measures: single- and dual-task tandem gait and reaction time (RT; simple and clinical) assessments. They then completed monthly surveys for a year after RTP, which assessed exposure to injury (sport participation) and subsequent injuries (musculoskeletal or concussions) sustained. We used Poisson regression models to calculate injury rate ratios with the number of subsequent injuries sustained as the outcome, adjusted for RTP clearance time and competitive exposures for each measure.

RESULTS

Forty-one participants were included (age = 15.5 ± 1.3 yr, 56% female, 9.6 ± 4.6 d postconcussion; 38.0 ± 31.5 d to RTP). A higher injury rate per athletic exposure was observed for simple RT ≥ 505 ms versus <505 ms (injury rate ratio = 2.96, 95% confidence interval = 1.41-6.60, P = 0.005). Injury rates did not significantly differ by Pittsburgh Sleep Quality Index or Tampa Scale of Kinesiophobia scores, single/dual-task tandem gait time, or clinical RT.

CONCLUSIONS

Simple RT may be one risk factor that is associated with higher rates of subsequent injury after adolescent concussion. A simple RT measure incorporated into a comprehensive concussion RTP assessment may identify some individuals at higher risk of subsequent injury in the year after concussion, although further research is needed to better understand this relationship.