Concussion Symptomatology by Symptom Resolution Time in US High School Athletes: Findings From the National Athletic Treatment, Injury and Outcomes Network High School Surveillance Program (NATION-SP).

Context: Concussions incurred during high school athletics are a significant health concern, and studies examining concussions with a symptom resolution time (SRT) of 15 to 28 days have been limited.

Objective: To compare concussions that had an SRT of 15 to 28 days with concussions that had an SRT of greater than 28 days among US high school athletes.

Design: Descriptive epidemiology study.

Setting: Secondary school athletic training clinics.

Patients Or Other Participants: Secondary school athletes.

Main Outcome Measure(s): Concussion frequency, symptom number, and symptom prevalence.

Results: Among all 917 reported concussions (of which 50.8% had missing SRT), 88 had an SRT recorded as 15 to 28 days, and 29 had an SRT recorded as greater than 28 days. Greater frequencies of concussions with an SRT of 15 days or more were reported in boys' sports (n = 78) than girls' sports (n = 39). Boys' football (51.7%) and girls' basketball (11.5%) accounted for the largest proportions of all reported concussions with an SRT of 15 to 28 days; boys' football (58.6%) accounted for the greatest proportion of concussions reported with an SRT greater than 28 days. The average number of symptoms was 6.3 ± 3.4 for concussions with an SRT of 15 to 28 days and 7.2 ± 3.8 for those with an SRT greater than 28 days. The most frequently reported symptoms in concussions with both SRT of 15 to 28 days and greater than 28 days were headache, dizziness, sensitivity to light, and difficulty concentrating. The prevalence of irritability was higher in concussions with an SRT of 15 to 28 days as compared with concussions with an SRT greater than 28 days (26.1% versus 13.8%); visual problems (48.3% versus 35.2%) and hyperexcitability (24.1% versus 15.9%) were more prevalent in concussions with an SRT greater than 28 days, although differences were not statistically significant.

Conclusions: Symptom prevalence and total count were comparable between concussions with an SRT of 15 to 28 days and those with an SRT of greater than 28 days with no statistically significant difference, suggesting that symptom burdens within these groups are more similar than they are different.