Objective: Establish sex, age, and concussion history-specific normative baseline sport concussion assessment tool 3 (SCAT3) values in adolescent athletes.
Design: Prospective cohort.
Setting: Seven Wisconsin high schools.
Participants: Seven hundred fifty-eight high school athletes participating in 19 sports.
Independent variables: Sex, age, and concussion history.
Main outcome measures: Sport Concussion Assessment Tool 3 (SCAT3): total number of symptoms; symptom severity; total Standardized Assessment of Concussion (SAC); and each SAC component (orientation, immediate memory, concentration, delayed recall); Balance Error Scoring System (BESS) total errors (BESS, floor and foam pad).
Results: Males reported a higher total number of symptoms [median (interquartile range): 0 (0-2) vs 0 (0-1), P = 0.001] and severity of symptoms [0 (0-3) vs 0 (0-2), P = 0.001] and a lower mean (SD) total SAC [26.0 (2.3) vs 26.4 (2.0), P = 0.026], and orientation [5 (4-5) vs 5 (5-5), P = 0.021]. There was no difference in baseline scores between sex for immediate memory, concentration, delayed recall or BESS total errors. No differences were found for any test domain based on age. Previously, concussed athletes reported a higher total number of symptoms [1 (0-4) vs 0 (0-2), P = 0.001] and symptom severity [2 (0-5) vs 0 (0-2), P = 0.001]. BESS total scores did not differ by concussion history.
Conclusion: This study represents the first published normative baseline SCAT3 values in high school athletes. Results varied by sex and history of previous concussion but not by age. The normative baseline values generated from this study will help clinicians better evaluate and interpret SCAT3 results of concussed adolescent athletes.