Table 1.

—Baseline Demographics by Race

Variable	Caucasian	African American	t (df)	P Value
Age, y	65 ± 8.3	60 ± 8.7	−8.35 (314)	< .001a
FEV1 % predicted	56 ± 23.8	55 ± 21.2	−0.61 (354)	.54
Pack-y smoking history	54 ± 26.9	42 ± 22.3	−7.34 (375)	< .001a
Current smokers	336 (32)	121 (54)	NA	< .001a
Women	484 (46)	113 (50)	NA	.27
BMI, kg/m2	27.8 ± 6.0	27.8 ± 6.2	0.07 (318)	.94
Height, cm	170 ± 9.7	170 ± 9.5	0.13 (330)	.90
6-min walk distance, m	381 ± 135.2	298 ± 119.4	−9.25 (356)	< .001a
Education
Less than HS	91 (9)	60 (27)	NA	< .001a
Graduated HS	267 (25)	63 (28)
More than HS	691 (66)	101 (45)

Data are presented as mean ± SD or No. (%), unless otherwise indicated. df = degrees of freedom; HS = high school; NA = not applicable.

^aThese comparisons remain statistically significant after controlling for multiple comparisons using the false discovery rate procedure.^15,16