Table 2.

Respondent characteristics at baseline by level of cigarette consumption (n = 2,980)

Variable	1	2	3	4	p value; H0: 1 = 2	p value; H0: All categories equal
	≤5 CPD, nondaily (n = 677)	≤5 CPD, daily (n = 580)	6–10 CPD (n = 1,258)	>10 CPD (n = 465)
Demographics (%)
Female	59	67	61	48	.08	<.001
Age (years)					.06	<.001
18–24	26	23	21	14
25–44	53	47	51	45
45–64	17	24	25	35
65+	3	6	4	6
White	79	79	76	88	.96	<.001
Married	32	35	43	40	.59	.03
Socioeconomic status (%)
Education ≤ high school	21	44	52	56	<.001	<.001
Income					.001	<.001
<$20,000	12	14	10	14
$20,000–$50,000	25	34	34	32
>$50,000	54	31	40	38
Unknown	9	20	16	15
Smoking behavior
Mean number of CPD	1.7	3.8	9.2	23.9	<.001	<.001
Started smoking at age ≤16 years (%)	35	49	45	59	.004	<.001
Smoke first cigarette ≤30 min after waking (%)	7	18	37	74	<.001	<.001
Social smoking (smokes more often with friends) (%)	59	29	23	11	<.001	<.001
Quitting behavior and intentions (%)
Made quit attempt in the past year	57	46	44	39	.03	<.001
Plans to quit smoking					.003	<.001
In the next 30 days	41	33	31	26
In the next 6 months	25	32	34	34
After 6 months	27	19	22	19
No plan to quit entirely	8	16	12	22
Self-efficacy (very sure I can quit for ≥30 days)	69	49	41	27	<.001	<.001
Social environment (%)
At least half of friends smoke	39	45	53	62	.17	<.001
No-smoking policies (%)
Smoking banned in household	55	49	42	26	.23	<.001
Smoking banned in workplace	50	41	42	31	.05	<.001

Note. CPD = cigarettes per day.