Symptom Exacerbation and Adverse Events During a Randomized Trial of Early-Stage Rehabilitation After Sport-Related Concussion: Safety Outcomes From the Active Rehab Study.

Context: Authors of few studies have used randomized controlled trials (RCTs) to quantify clinical intervention safety of rehabilitation after sport-related concussion across sport levels.

Objective: Describe symptom exacerbation and adverse events (AEs) associated with two concussion rehabilitation interventions.

Design: Cluster RCT (NCT02988596).

Setting: Sports medicine clinic and field settings.

Patients Or Other Participants: The RCT enrolled 251 concussed athletes (median age = 20 years; female, n = 48) across 28 sites from New Zealand professional rugby (n = 31), Canadian professional football (n = 52), US/Canadian colleges (n = 128) and US high schools (n = 40).

Interventions: Two medically supervised interventions: (1) enhanced graded exertion (EGE): international return-to-sport strategy and sport-specific activities only (EGE only, n = 119); and (2) multidimensional rehabilitation (MDR) followed by EGE: early symptom-directed exercises once symptoms were stable, followed by EGE after symptoms resolved (MDR + EGE, n = 132).

Main Outcome Measure(s): Primary outcomes were intrasession total symptom severity score exacerbation and significant intersession (increase 10+ severity points) sustained total symptom severity exacerbation, each measured with the Postconcussion Symptom Scale (132 total severity points on scale). Reported AEs were also described. Activity-based rehabilitation sessions (n = 1437) were the primary analysis unit. Frequencies, proportions, medians, and interquartile ranges were calculated for outcomes by treatment group.

Results: The 251 postinjury participants completed 1437 (MDR + EGE = 819, EGE only = 618) activity-based intervention sessions. A total of 110 and 105 participants contributed data (those missing had no documented session data) to at least 1 activity-based session in the MDR + EGE and EGE-only arms, respectively. Intrasession symptom exacerbations were equivalently low in MDR + EGE and EGE-only arms (MDR + EGE: 16.7%, 95% CI = 14.1%, 19.1%; EGE only: 15.7%, 95% CI = 12.8%, 18.6%). In total, 9/819 MDR + EGE sessions (0.9%) and 1/618 EGE-only sessions (0.2%) resulted in a presession to postsession symptom exacerbation beyond a 10+ severity point increase; 8/9 resolved to <10 points by the next session. Two study-related AEs (1 in each arm) were reported.

Conclusions: Participants in MDR + EGE and EGE-only activities reported equivalently low rates of symptom exacerbation.