Table 2.

Prospective predictors of making a quit attempt between Waves 1 and 2 (n=3863^{^})

Factors	n	% Quit attempt	Crude OR	95% CI	Adjusted OR	95% CI
Factors	n	% Quit attempt	City				^***	^***
Beijing	708	23.0	Ref^#		Ref
Shenyang	582	30.4	1.46	1.14–1.87^**	1.24	.93–1.65
Shanghai	703	13.2	.51	.39–.67^***	.65	.48–.88^**
Changsha	646	28.2	1.31	1.03–1.68^*	1.28	.96–1.69
Guangzhou	555	25.0	1.12	.86–1.45	1.32	.99–1.77
Yinchuan	659	34.1	1.73	1.37–2.19^***	1.30	.99–1.72
Age at recruitment				^**		^*
18–39	635	26.8	Ref		Ref
40–54	1892	22.8	.81	.66–.99^*	1.01	.80–1.27
55+	1326	28.4	1.09	.88–1.34	1.27	.98–1.63
Sex				NS		NS
Female	192	30.2	Ref		Ref
Male	3661	25.2	.78	.57–1.07	1.02	.69–1.48
Education				^*		NS
Low	526	30.0	Ref		Ref
Moderate	2553	24.6	.76	.62-.94^*	.87	.67–1.12
High	773	24.8	.77	.60–.98^*	.76	.56–1.05
Majority/minority				^**		NS
Others	199	35.7	Ref		Ref
Han	3654	24.8	.59	.44–.80^**	.80	.56–1.13
Income				^*		NS
Low	784	27.3	Ref		Ref
Moderate	1744	26.7	.97	.80–1.17	.97	.78–1.22
High	1067	22.0	.75	.61–.93^**	.84	.65–1.09
Don’t know	256	25.4	.91	.66–1.25	1.01	.69–1.45
Longest time quit				^***		^***
Never tried	1815	15.6	Ref		Ref
Less than 1 month	831	34.3	2.81	2.32–3.41^***	1.62	1.29–2.04^***
1–6 months	743	35.3	2.94	2.41–3.58^***	1.59	1.27–2.01^***
>6 months	444	31.5	2.48	1.96–3.15^***	1.41	1.08–1.84^*
Tried to quit within last year				^***		^***
Yes tried	639	47.6	Ref		Ref
Not tried	3175	20.8	.29	.24–.35^***	.61	.49–.76^***
Daily/weekly smokers				^***		NS
Daily smoker	3604	24.5	Ref		Ref
Weekly smoker	249	38.6	1.93	1.48–2.52^***	1.11	.79–1.57
Cigarettes per day				^***		NS
<=10 CPD	1312	30.3	Ref		Ref
11–20 CPD	1885	23.4	.70	.60–.83^***	1.04	.86–1.27
21–30 CPD	340	19.4	.56	.41–.74^***	.89	.63–1.26
31+ CPD	296	22.6	.67	.50–.91^**	1.18	.83–1.67
Time to first cigarette				^***		^**
61+ min/don’t know	1250	32.6	Ref		Ref
31–60 min	547	24.7	.68	.54–.85^**	.72	.56–.93^*
6–30 min	952	21.5	.57	.47–.70^***	.67	.53–.84^***
<=5 min	1104	20.9	.55	.45–.67^***	.67	.54–.88^***
Self efficacy				^***		^*
Not at all sure	1641	16.0	Ref		Ref
Somewhat sure	942	30.5	2.31	1.90–2.79^***	1.33	1.06–1.67^*
Very sure	511	36.6	3.04	2.43–3.79^***	1.38	1.05–1.78^*
Extremely sure	483	39.5	3.44	2.75–4.31^***	1.27	.94–1.69
Don’t know	274	18.6	1.20	.86–1.68	.87	.59–1.25
Intention to quit				^***		^***
No intention	2477	16.6	Ref		Ref
Beyond 6 months/don’t know	816	35.5	2.76	2.31–3.30^***	1.58	1.28–1.95^***
Within 6 months	235	44.7	4.05	3.07–5.35^***	2.37	1.71–3.23^***
Within 1 month	306	54.6	6.02	4.69–7.72^***	2.61	1.93–3.53^***
Outcome expectancy				^***		NS
Not at all	774	16.1	Ref		Ref
Somewhat/don’t know	1753	22.2	1.48	1.19–1.85^***	1.01	.78–1.28
Very much	1322	35.1	2.81	2.25–3.51^***	1.05	.81–1.39
Worries about health				^***		NS
Not at all	1332	18.2	Ref		Ref
Somewhat/don’t know	1835	24.4	1.47	1.24–1.75^***	1.08	.86–1.32
Very much	683	41.4	3.19	2.59–3.92^***	1.22	.93–1.59
Enjoy smoking too much				^***		NS
Other	1721	28.6	Ref		Ref
Agree	2131	22.8	.74	.64–.85^***	.88	.74–1.04
Overall opinion about smoking				^***		^*
Other	1812	17.5	Ref		Ref
Negative	1476	29.1	1.93	1.63–2.28^***	1.22	1.01–1.47^*
Very negative	564	41.3	3.32	2.69–4.09^***	1.45	1.12–1.87^**
Smoking restrictions at home				^***		^*
No home bans	3442	24.3	Ref		Ref
Home bans	411	34.3	1.62	1.31–2.02^***	1.36	1.05–1.74^*

^{^}

Note: “n” in multivariate analysis is slightly less due to missing cases.

Ref: reference value.

Significant at p<0.05;

^**

p<0.01;

^***

p<0.001.

NS=not significant.