Table 1:

Clinical characteristics of patients with SPMS

	Nonimpaired (n = 20)	Cognitively Impaired (n = 25)	P Value
Age (y)	54.5 (49.3–62.3)	55.0 (47.5–61.5)	.954^{^a}
Sex (F/M)	11/9	16/9	.540^{^b}
Education level (yr)	15.5 (13.0–17.8)	14.0 (13.0–17.0)	.619^{^a}
Disease duration (yr)	18.5 (10.5–20.8)	19.0 (12.0–28.5)	.192^{^a}
EDSS (score)	6.0 (6.0–6.5)	6.5 (6.0–6.5)	.249^{^a}
BDI (score)	6.5 (5.0–11.75)	9.0 (7.5–13.5)	.067^{^a}

Note:—BDI indicates Beck Depression Inventory; EDSS, Expanded Disability Status Scale.
↵a Wilcoxon rank sum test (median [interquartile range]).
↵b Pearson χ² test.