Frequency and timing of same-season repeat concussion in NCAA Concussion Study and CARE Consortium cohorts
| NCAA Concussion Study (1999–2001) | CARE Consortium (2014–2017) | |
| Initial concussions (n) | 184 | 701 |
| Same-season repeat concussion (n) | 12 | 27 |
| Rate of same-season repeat concussion (% of athletes with initial concussion) | 6.52 | 3.85 |
| Interval between first and repeat concussion (days) | ||
| Mean (SD) Median | 5.59 (3.89) 4.0 | 56.41 (32.49) 49 |
| Repeat concussions | ||
| <7 days of initial injury, n (%) | 9 (75.0) | 1 (3.7) |
| <10 days of initial injury, n (%) | 11 (91.7) | 1 (3.7) |
Interval between first and repeat concussion (mean difference=50.82 days; 95% CI 38.37 to 63.27; p<0.0001, d=2.78).
Rate of repeat concussion, χ2 test p=0.17.
Repeat concussion in <7 days, Fisher’s exact test p<0.0001.
Repeat concussion in <10 days, Fisher’s exact test p<0.0001.
CARE, Concussion Assessment, Research and Education; NCAA, National Collegiate Athletic Association.