Comparing psychometrics of baseline symptom scores on the Sport Concussion Assessment Tool 5th and 3rd Edition Symptom Evaluation over one week

In sports, baseline assessment of self-reported concussion-related symptoms with the Sport Concussion Assessment Tool (SCAT) is often implemented as part of sports-related concussion protocols. However, changes in baseline instructions for symptom reporting on the Symptom Evaluation of the SCAT 5th Edition (SCAT5: "how he/she typically feels") from the SCAT 3rd Edition (SCAT3: "how you feel now") have yet to be comprehensively studied. The present study used a within-subjects design over a one-week test-retest period to compare baseline distributional characteristics, within-individual reporting patterns, and test-retest reliability correlations in a sample of 395 undergraduate students. Results indicated higher baseline symptom reporting on the symptom scale of the SCAT5 than the SCAT3, at Time 1 than Time 2, and in females than males; there were no statistically significant interaction effects. Baseline within-individual reporting patterns were similar in males and females for the most part, though males more often endorsed the same level of symptoms across the SCAT5 and SCAT3 symptom scales. Comparisons of baseline test-retest reliability coefficients demonstrated mixed findings, but significant results consistently showed higher test-retest reliability for symptom variables on the symptom scale of the SCAT5 than the SCAT3. These findings provide important considerations for clinicians when using the SCAT5 Symptom Evaluation to assess baseline concussion-related symptoms.