Table 1

Sociodemographic and smoking-related characteristics of current smokers who were surveyed at Wave 2 (n=4568*)

	Followed up at Wave 3 (n=3677)		Not followed up at Wave 3 (n=891)		p Value for group comparison (followed vs not-followed)
	n	%Followed-up	n	% Not followed-up	p Value for group comparison (followed vs not-followed)
City					0.000†
Beijing	662	18.0	84	9.4
Shenyang	492	13.4	276	30.9
Shanghai	673	18.3	94	10.6
Changsha	644	17.5	102	11.5
Guangzhou	656	17.8	133	14.9
Yinchuan	550	14.9	202	22.7
Gender (male)	3483	94.7	854	95.9	0.17†
Majority (Han)	3490	94.9	841	94.5	0.59†
Marital status (% married)	3306	90.3	798	90.0	0.76†
Age (years)					0.002†
18–24	33	0.9	10	1.1
25–39	554	15.1	179	20.1
40–54	1822	49.6	425	47.7
55+	1268	34.5	277	31.1
Education					0.01†
Low	436	11.9	99	11.2
Moderate	2474	67.7	565	63.8
High	746	20.4	222	25.1
Income					0.10†
Low	586	16.0	168	18.8
Moderate	1664	45.3	408	45.8
High	1179	32.1	256	28.7
Don't know	241	6.5	59	6.6
Daily/weekly smokers					0.53†
Daily smokers	3470	94.4	836	93.8
Weekly smokers	207	5.6	55	6.2
Intention to quit					0.56†
No intention	2446	67.0	589	66.6
Beyond 6 months/don't know	680	18.6	149	16.9
Within 6 months	278	7.6	81	9.1
Within 1 month	240	6.6	63	7.1
HSI (mean±SD)	3549	2.36 (0.03)	853	2.33 (0.06)	0.63‡
Length of last serious quit attempt					0.90†
Never tried	1627	44.6	386	43.7
<1 month	977	26.7	240	27.2
1–6 months	755	20.7	180	20.4
>6 months	290	7.9	76	8.6
Self-efficacy					0.30†
Not at all sure	1764	48.4	408	46.0
Somewhat sure	976	26.8	237	26.7
Very sure	408	11.2	113	12.7
Extremely sure	342	9.4	81	9.1
Don't know	152	4.1	48	5.4

*For characteristics of the 4732 smokers who were surveyed at Wave 1, please refer to Li et al. (2011) paper.
†χ² test results.
‡T test results. HSI, Heaviness of Smoking Index (we presented the mean of HSI and its SD).