Sport Concussion Assessment Tool: Interpreting day-of-injury scores in professional ice hockey players.

OBJECTIVES: To characterize the clinical utility of Sport Concussion Assessment Tool 3 (SCAT3) baseline and normative reference values for the assessment of acute concussion; and to identify the sensitivity of each SCAT3 subcomponent to the acute effects of concussion.

DESIGN: Prospective cohort.

METHODS: The day-of-concussion SCAT3 results (n=27) of professional male ice hockey players (mean age=27, SD=4) were compared to athlete's individual baseline and to the league's normative reference values. Normative cutoffs corresponding to 10th percentile and natural distribution change cutoffs corresponding to 90th percentile cumulative frequency were considered uncommon.

RESULTS: The percentages of the players with uncommon day-of-injury performance, when post-injury scores were compared to individual baseline versus (vs.) normative values, were as follows: symptoms: 96% vs. 100% (post-injury score: M=12, Md=12, SD=4; severity M=26, Md=23, SD=13); Standardized Assessment of Concussion (SAC): 33% vs. 27% (post-injury M=25, Md=26, SD=3); modified-BESS (M-BESS): 46% vs. 46% (post-injury M=7, Md=5, SD=7); Tandem Gait: 18% vs. 31% (post-injury M=11, Md=12, SD=4); coordination: both 8%. The number and severity of post-injury symptoms were significantly greater, with extremely large effect sizes (Cohen's d=2.44-3.92), than normative values and individual baseline scores. The post-injury SAC score was significantly lower relative to both baseline (d=0.68) and normative values (d=0.88). The post-injury M-BESS performance was significantly worse when compared to both individual baseline (d=1.06) and league normative values (d=1.46). No significant day-of-injury Tandem Gait deficits were observed using either comparison method.

CONCLUSIONS: SCAT3 league normative values were as sensitive as individual baseline scores during day-of-injury assessments. Symptoms were the most sensitive post-concussion component of the SCAT3.