Table 1.

Covariates in Relation to Infectious Burden Index (IBI)

Variable	n (%)	IBI, Mean±Standard Deviationb
Age at neuropsychiatric assessmenta
<60	16 (3)	0.74±0.50
60–65	139 (24)	1.01±0.32
>65	433 (74)	1.00±0.34
Sexa
Male	225 (38)	0.95±0.38
Female	363 (62)	1.02±0.31
Education
≥High school	248 (42)	0.86±0.40
<High school	340 (58)	1.09±0.25
Race and ethnicitya
White	80 (14)	0.66±0.43
Black	94 (16)	0.99±0.38
Hispanic	414 (70)	1.06±0.27
Medicaid or uninsured
Yes	308 (52)	1.07±0.26
No	280 (48)	0.91±0.39
Magnetic resonance imaging–defined infarction
Yes	63 (11)	0.93±0.35
No	525 (89)	1.00±0.34
White matter hyperintensity volume
> 0.35	294 (50)	0.99±0.34
≤ 0.35	294 (50)	1.00±0.34
Diabetes mellitusa
Yes	104 (18)	1.06±0.27
No	484 (82)	0.98±0.35
Hypertension
Yes	401 (68)	1.00±0.33
No	187 (32)	0.97±0.36
Hypercholesterolemia
Yes	384 (65)	0.98±0.34
No	204 (35)	1.02±0.33
Body mass indexa
Normal	153 (26)	0.94±0.39
Overweight	268 (46)	0.99±0.33
Obese	165 (28)	1.04±0.30
Moderate alcohol usea
Yes	233 (40)	0.95±0.37
No	355 (60)	1.02±0.32
Moderate to heavy physical activity
Yes	53 (9)	0.90±0.42
No	533 (91)	1.00±0.33
Smoking
Never	270 (46)	1.01±0.33
Former	226 (38)	0.97±0.35
Current	92 (16)	0.99±0.35

^ap<.05 using t-tests or analysis of variance.

^bRange=0–1.35