Sample and acute injury characteristics for NCAA Concussion Study and CARE Consortium cohorts
| Characteristics | NCAA Concussion Study (1999–2001) Mean (SD) | CARE Consortium (2014–2017) Mean (SD) | Mean difference (95% CI) | P value |
| Concussions (n)† | 184 | 701 | ||
| Age (years)* | 19.70 (1.46) | 19.03 (1.3) | −0.67 (−0.9 to −0.43) | <0.0001 |
| Academic year* | 2.55 (1.18) | 1.81 (1.03) | −0.74 (−0.92 to −0.55) | <0.0001 |
| Height (inches) | 73.17 (2.69) | 73.5 (2.94) | 0.33 (−0.13 to 0.78) | 0.16 |
| Body weight (lb) | 227.91 (45.25) | 229.38 (45.17) | 1.47 (−6 to 8.93) | 0.70 |
| Participation in football (years) | 8.94 (2.94) | 9.38 (3.28) | 0.44 (−0.06 to 0.94) | 0.09 |
| Prior concussions (n)* | 0.55 (0.92) | 0.69 (0.97) | 0.14 (−0.01 to 0.3) | 0.06 |
| ADHD | 4.3% | 7.4% | 0.19 | |
| Learning disorder | 1.6% | 4.4% | 0.09 | |
| NCAA sites | ||||
| Division I Division II Division III | 19 3 3 | 20 5 5 | 0.76 |
| Acute injury characteristics | ||||
| LOC, n (%) Median duration (s) Mean duration (s) | 12 (6.3%) 30.0 52.9 (67.42) | 35 (5.1%) 5.0 19.06 (51.78) | −33.84 (−75.77 to 8.09) | 0.41 0.13 |
| PTA, n (%) Median duration (min) Mean duration (min) | 44 (24.0%) 30.0 104.4 (282.4) | 104 (15.1%) 10.0 37.74 (118.45) | −66.66 (−154.3 to 20.98) | 0.004 0.14 |
| LOC or PTA (%) | 28.3 | 17.9 | 0.003 | |
*Effect sizes: age (d=−0.47), academic year (d=−0.64), number of prior concussions (d=0.15).
†Concussion definition: (1) NCAA Concussion Study: Concussion was defined according to the American Academy of Neurology Guideline for Management of Sports Concussion, as an injury resulting from a blow to the head causing an alteration in mental status and one or more symptoms of headache, nausea, vomiting, dizziness/balance problems, fatigue, difficulty sleeping, drowsiness, sensitivity to light or noise, blurred vision, memory difficulty and difficulty concentrating.22 23 (2) CARE Consortium: Concussion was defined according to the consensus definition from the US Department of Defense (DoD) evidence-based guidelines, which define concussion as ‘a change in brain function following a force to the head, which may be accompanied by temporary loss of consciousness, but is identified in awake individuals with measures of neurologic and cognitive dysfunction.’24
ADHD, attention-deficit hyperactivity disorder;CARE, Concussion Assessment, Research and Education; LOC, loss of consciousness;NCAA, National Collegiate Athletic Association; PTA, post-traumatic amnesia.