Table 2. Neurocognitive testing results.

Parameter		Overall§ (n = 557)	Caucasian ethnicity (n = 381)	Black ethnicity (n = 156)	Other ethnicity (n = 20)	P-value for difference between Caucasian vs. Black ethnicity
Standard normative data	NPZ-5 score	−0.5 (−1.2, −0) [95%CI −0.8, −0.6]	−0.3 (−0.7, 0.1) [95%CI −0.4, −0.3]	−1.4 (−2, −.8) [95%CI −1.8, −1.4]	−0.8 (−1.3, −0.4) [95%CI −1.3, −0.6]	<0.001
	Overall NPZ-5 score >1 SD below population mean	179 (32)	66 (17)	104 (67)	9 (45)	<0.001
	At least 2 individual tests with z-score >1 SD below population mean	285 (51)	144 (38)	127 (81)	14 (70)	<0.001
Adjusted normative data¶	NPZ-5 score		−0.8 (−1.3, −0.3)	−1.1 (−1.6, −0.6)		<0.001
	Overall NPZ-5 score>1 SD below population mean		145 (38)	69 (55)		0.001
	At least 2 individual tests with z-score>1 SD below population mean		236 (62)	86 (68)		0.20

Table 2 legend: ^§patients with complete neurocognitive data including patients of ethnicity other than Caucasian or Black (n = 20); IQR  =  interquartile range, SD  =  standard deviation; ^¶Excludes all patients of ethnicity other than Caucasian and Black, as well as 30 subjects of Black ethnicity who fell outside the age range covered by the adjusted normative data; NPZ-5 results using standard normative data in these 30 patients were similar to those of the other 126 patients. Data are number (%) or median (interquartile range).