Table 1 Dichotomized Cohort Demographics

Age

15.3 ± 1.5

15.4 ± 1.6

0.60

Grade Level

9.23 ± 1.60

9.08 ± 1.65

0.002

Gender

 Male

762 (60.5)

6860 (66.6)

< 0.0001

 Female

498 (39.5)

3443 (33.4)

< 0.0001

Contact Sports

1019 (80.9)

7910 (76.8)

0.001

 Football

504 (40.0)

4041 (39.2)

0.59

  Higher Risk Position

363 (28.8)

2255 (21.9)

< 0.0001

   Linesman

276 (21.9)

1572 (15.3)

< 0.0001

   Wide Receiver

68 (5.40)

543 (5.27)

0.85

   Cornerback

19 (1.51)

140 (1.35)

0.67

  Lower Risk Position

134 (10.6)

951 (9.23)

0.11

   Running Back/ Fullback

58 (4.60)

440 (4.27)

0.58

   Quarterback

38 (3.02)

239 (2.32)

0.13

   Tight End

24 (1.90)

143 (1.39)

0.15

   Safety

14 (1.11)

129 (1.25)

0.67

 Soccer

176 (14.0)

1268 (12.3)

0.09

 Basketball

108 (8.57)

921 (8.94)

0.67

 Lacrosse

78 (6.19)

628 (6.10)

0.89

 Cheerleading/ Gymnastics

87 (6.90)

473 (4.59)

0.0003

  Wrestling/ Boxing/ Martial Arts

48 (3.81)

375 (3.64)

0.76

  Water Polo/ Diving

18 (1.43)

204 (1.98)

0.18

Limited Contact Sports

192 (15.2)

1620 (15.7)

0.20

 Baseball/ Softball

76 (6.03)

735 (7.13)

0.15

 Volleyball

94 (7.46)

664 (6.44)

0.17

 Track and Field

22 (1.75)

221 (2.15)

0.34

Years of Experience

2.26 ± 2.54

2.11 ± 2.53

0.04

Games Missed

1.64 ± 3.49

0.64 ± 1.93

< 0.0001

History of Concussions

 0

673 (53.4)

7070 (68.6)

< 0.0001

 1

344 (27.3)

1909 (18.5)

< 0.0001

 2+

226 (17.9)

750 (7.28)

< 0.0001

Type of Historic Concussion

 Confusion

598 (47.5)

1826 (17.7)

< 0.0001

 Anterograde Amnesia

375 (29.8)

1130 (11.0)

< 0.0001

 Retrograde Amnesia

280 (22.2)

836 (8.11)

< 0.0001

 Loss of Consciousness

219 (17.4)

650 (6.31)

< 0.0001

Neuropsychiatric Comorbidities

 Depression/ Anxiety

127 (10.1)

304 (2.95)

< 0.0001

 ADHD

71 (5.63)

507 (4.92)

0.27

 DLD

50 (3.97)

272 (2.64)

0.007

 Dyslexia

37 (2.94)

189 (1.83)

0.008

 Autism

11 (0.87)

33 (0.32)

0.003

 Epilepsy

34 (2.70)

94 (0.91)

< 0.0001

 Substance Use Disorder

12 (0.95)

13 (0.13)

< 0.0001

Special Education

38 (3.02)

174 (1.69)

0.001

Speech Therapy

114 (9.05)

613 (5.95)

< 0.0001

English as Primary Language

1251 (99.3)

10,243 (99.3)

0.57

Baseline ImPACT Composite

 Symptom Score

10.37 ± 13.59

5.04 ± 8.84

< 0.0001

  Migraine Cluster

3.28 ± 0.23

1.31 ± 0.05

< 0.0001

   Headache

1.08 ± 0.04

0.42 ± 0.009

< 0.0001

   Vomiting

0.09 ± 0.01

0.04 ± 0.003

< 0.0001

   Nausea

0.20 ± 0.02

0.09 ± 0.005

< 0.0001

   Balance

0.24 ± 0.02

0.10 ± 0.005

< 0.0001

   Dizziness

0.37 ± 0.03

0.14 ± 0.006

< 0.0001

   Sensitivity to Light

0.43 ± 0.03

0.16 ± 0.006

< 0.0001

   Sensitivity to Noise

0.31 ± 0.02

0.11 ± 0.005

< 0.0001

   Numbness

0.18 ± 0.02

0.08 ± 0.004

< 0.0001

   Visual

0.39 ± 0.03

0.17 ± 0.007

< 0.0001

  Cognitive Cluster

2.78 ± 0.18

1.49 ± 0.04

< 0.0001

   Fatigue

0.58 ± 0.03

0.34 ± 0.009

< 0.0001

   Drowsiness

0.54 ± 0.03

0.29 ± 0.008

< 0.0001

   Slowed Down

0.26 ± 0.03

0.15 ± 0.006

< 0.0001

   Fogginess

0.22 ± 0.02

0.11 ± 0.005

< 0.0001

   Concentration

0.71 ± 0.04

0.38 ± 0.009

< 0.0001

   Memory

0.46 ± 0.03

0.22 ± 0.007

< 0.0001

  Sleep Cluster

2.05 ± 0.11

1.18 ± 0.03

< 0.0001

   Trouble Falling Asleep

0.77 ± 0.04

0.44 ± 0.01

< 0.0001

   Sleeping More

0.40 ± 0.03

0.19 ± 0.007

< 0.0001

   Sleeping Less

0.89 ± 0.04

0.55 ± 0.01

< 0.0001

  Neuropsychiatric Cluster

2.03 ± 0.13

1.10 ± 0.03

< 0.0001

   Irritability

0.51 ± 0.03

0.27 ± 0.008

< 0.0001

   Nervousness

0.61 ± 0.04

0.35 ± 0.009

< 0.0001

   Sadness

0.41 ± 0.03

0.21 ± 0.007

< 0.0001

   More Emotional

0.50 ± 0.03

0.27 ± 0.009

< 0.0001

Verbal Memory

81.09 ± 0.68

81.66 ± 0.27

0.12

Visual Memory

69.38 ± 0.87

70.73 ± 0.35

0.004

Processing Speed

34.6 ± 0.45

33.9 ± 0.18

0.004

Reaction Time

0.64 ± 0.06

0.64 ± 0.02

0.90