Factor Structure for the Sport Concussion Assessment Tool Symptom Scale in Adolescents After Concussion

Objective: To examine the factor structure of the Sport Concussion Assessment Tool-5 (SCAT5) symptom scale in adolescents on their initial presentation to a concussion clinic within the typical recovery period after concussion (ie, <30 days). We hypothesize that the SCAT5 symptoms represent various clinically meaningful groups. A secondary purpose was to examine the effects of sex on the factor structure of the SCAT5 symptom scale. Study Design: Retrospective cross-sectional analysis. Setting: Tertiary, institutional. Patients: Nine hundred eighty-one adolescents (45% women) aged between 13 and 18 years. Independent Variables: Adolescents completed the SCAT5 symptom scale. Main OutcomeMeasures: The factor structure of SCAT5 examined using a principal axis factor analysis. Results: A 5-factor structure model explained 61% of the variance in symptoms. These 5 factors are identified as Energy (17%), Mental Health (13%), Migrainous (13%), Cognitive (9%), and Vestibulo-Ocular (9%). A similar 5-factor model emerged for each sex, and the proportion of variance in symptoms explained by the 5-factor model was comparable between the sexes. Conclusions: The findings of this report indicate that the SCAT5 symptoms aggregated into 5 delineated factors, and these factors were largely consistent across the sexes. The delineation of symptoms into 5 factors provides preliminary validation for the presence of different concussion phenotypes. Confirmatory factor analysis is warranted to examine the applicability and clinical utility of the use of the 5-factor structure in a clinical setting.