Table 2:

Regression-based z scores for postseason ImPACT composite scores for football players (n = 63) and control athletes (n = 34)^{^a}

ImPACT Composite Score	Football Players (n = 63)		Control Athletes (n = 34)	P Value of χ² Test
ImPACT Composite Score	z Scores (Mean) (SD)	Percentage < 1.5 SD	Percentage < 1.5 SD	P Value of χ² Test
Verbal Memory composite	−0.36 (1.28)	27	5.9	.01^{^b}
Visual Memory composite	−0.46 (1.02)	19	11.8	.36
Visual Motor composite	−0.24 (1.18)	20.6	3	.02^{^b}
Reaction Time composite	−0.45 (1.29)	23.8	5.9	.03^{^b}
Total Symptom Score	0.17 (1.60)	14.3	8.8	.44

↵a Variables controlled for in the regression models: 1) baseline scores, 2) age, 3) test-retest interval.
↵b Statistically significant.