TABLE 2.

CHARACTERISTICS OF LSC SUBJECTS BY ETHNICITY

Variable	Self-identified Ethnicity		P Value
	Hispanic	NHW
n	341	1,199
Age, yr, mean ± SD	54.4 ± 9.0	56.9 ± 9.5	1.4 × 10−5*
Sex, male, %	27.8	20.5	0.004†
Current smokers, %	73.0	54.2	5.1 × 10−10†
Pack-years, mean ± SD	34.3 ± 16.1	41.1 ± 20.9	<0.0001‡
10–26, %	34.0	22.8	2.2 × 10−6†
26–37, %	33.4	30.6
37–145, %	32.6	46.5
Age started smoking, yr, mean ± SD	16.3 ± 3.7	16.7 ± 3.6	0.09*
Duration of smoking, yr, mean ± SD	34.0 ± 8.8	33.6 ± 9.7	0.41‡
Age quit smoking, yr, mean ± SD	50.0 ± 9.7	48.5 ± 10.1	0.17*
Body mass index, kg/m2, mean ± SD	28.8 ± 5.4	28.1 ± 5.7	0.048*
16–25, %	24.9	33.4	0.01†
25–30, %	39.9	36.0
30–61, %	35.2	30.5
Annual household income, %§
Under $20,000	34.3	24.9	0.03†
$20,000–40,000	29.6	32.4
Over $40,000	36.1	42.7
Education level, %||
Less than college	55.6	24.5	<1 × 10−18†
Some college or above	44.4	75.5
Ancestry component, mean ± SD
European ancestry	0.62 ± 0.07	0.97 ± 0.03	NC¶
Native American ancestry	0.36 ± 0.07	0.03 ± 0.03	NC¶
African ancestry	0.02 ± 0.02	0.00 ± 0.02	NC¶
Chronic obstructive pulmonary disease, yes, %**	17.1	39.2	1.5 × 10−14†
Chronic mucous hypersecretion, yes, %††	35.9	30.5	0.06†

Definition of abbreviations: LSC = Lovelace Smokers cohort; NHW = non-Hispanic whites.

^*Student t test.

^†Chi-square test.

^‡Wilcoxon rank sum test.

^§Data missing for 340 subjects.

^||Data missing for 45 subjects.

^¶Not calculated.

^**Data missing for 14 subjects. Chronic obstructive pulmonary disease was defined according to the Global Initiative for Chronic Obstructive Lung Disease criteria (FEV₁/FVC < 0.70) (12).

^††Participants with self-identified cough productive of phlegm for at least 3 months per year for at least 2 consecutive years were considered to have chronic mucous hypersecretion (12).