Recovery duration and concussion severity in sport- and non-sport-related concussion among Pac-12 collegiate athletes: a retrospective cohort study

Objectives To examine non-sport- and sport-related concussion severity, clinical care frequency and delayed reporting in relation to recovery duration among collegiate athletes. Design Retrospective cohort study. Setting Pac-12 varsity collegiate athletes. Participants 461 collegiate male and female athletes Primary and secondary outcome measures The incidence of sport-related concussion (SRC) and non-sport-related concussion (NRC) were collected as well as times to recovery and return-to-play (RTP), symptom score and symptom severity and reported a loss of consciousness (LOC), retrograde amnesia (RGA) and post-traumatic amnesia (PTA) following concussion incidence. Results Among 461 concussions, 388 (84%) occurred within sport and 73 (16%) occurred outside of sport. NRC, on average, required 3.5 more days to become asymptomatic (HR: 0.73, 95%confidence interval: 0.56 to 0.96, p=0.02) and 7 more days to RTP (HR: 0.64, 95% confidence interval: 0.49 to 0.85, p<0.01) compared with SRC. NRC were associated with an increase of 1.83 (p=0.07) symptoms reported at the time of diagnosis, an increase of 6.95 (p=0.06) in symptom severity and a higher prevalence of reported LOC (22% NRC vs. 3% SRC, p < 0.001), PTA (15% NRC vs. 5% SRC, p< 0 .01) and RGA (10% NRC vs. 4% SRC, p = 0.06), compared with SRC. There was no significant difference in clinical care (p = 0.28) or immediate reporting (p=0.35) between NRC and SRC. Conclusion NRC were associated with greater severity and longer recovery duration when compared with SRC in a cohort of collegiate athletes.