Table 1

Analytical sample characteristics by lost to follow-up (n=2414)

		Not lost to follow-up	Lost to follow-up	p Value
		n=2273	n=141
Gender
Female	n=1293	44.4	49.9	0.260
Male	n=1121	55.6	50.1
Age
18–29	n=315	16.5	28.8	0.423
30–39	n=420	18.7	23.5
40–49	n=580	27.1	19.4
50–59	n=592	20.9	19.1
60–69	n=327	9.2	6.4
70+	n=180	7.7	2.8
Marital status
Married	n=1198	55.7	49.5	0.300
Single	n=1216	44.3	50.5
Education
High school or less	n=416	51.2	61.4	0.053
More than high school	n=725	48.8	38.6
Income quantile
Lowest	n=674	21.7	19.9	0.093
Second	n=611	25.6	13.2
Third	n=475	20.9	28.8
Fourth	n=374	17.4	26.1
Highest	n=280	14.3	12
Percent immigrant in neighbourhood
Lowest	n=1766	57.6	60.3	0.683
Middle	n=482	29.3	24.5
Highest tertile	n=160	13.1	15.2
Community size
1 500 000+	n=430	17.9	16.3	0.511
500 000–1 499 000	n=347	14.1	19.2
100 000–499 000	n=1064	44.4	39.7
10 000–99 999	n=444	18.4	19.2
Less than 10 000	n=673	23.7	24.8
Children at home
No	n=1465	60.71	60.28	0.919
Yes	n=949	39.29	39.72
Distance
No outlets with 500 m	n=776	32.9	24.6	0.135
1 or more outlets	n=1638	67.1	75.4

Perceived addiction (Question: How addicted to smoking do you feel yourself to be: very, somewhat, not at all addicted), any past use of pharmaceutical quit aids (ie, patch, gum, spray, buproprion, varenicline (yes/no)), any past use of behavioural quit aids (ie, self-help, counselling, group therapy (yes/no)). For the present study, high and moderate nicotine dependence was based on the Heaviness of Smoking Index and defined as a score of greater than 2.