Table 3.

Adjusted odds ratios (ORs) for associations between self-reported 7-day PPA at 6 months and demographic and smoking characteristics among respondents.

Variables			Odds ratio (95% CI)		P value
Age (years)
	<30	1		N/Aa
	30 to <40	1.32 (0.80-2.16)		.95
	≥40	1.77 (1.06-3.29)		.04
Age when started smoking (years)
	<18	1		N/A
	≥18	1.22 (0.87-1.70)		.26
Pack-years of cigarette smoking
	<20	1		N/A
	≥20	1.07 (0.68-1.68)		.77
Gender
	Male	1		N/A
	Female	1.02 (0.39-2.68)		.96
Education level
	Primary school or below	1		N/A
	Middle school	1.59 (0.42-5.97)		.53
	College/university or above	1.58 (0.43-5.83)		.53
Employment status
	Unemployed	1		N/A
	Working in a public service unit	0.98 (0.58-1.66)		.70
	Working in an enterprise	0.82 (0.51-1.32)		.28
Marital status
	Unmarried	1		N/A
	Married	0.57 (0.34-0.93)		.03
	Divorced	0.58 (0.26-1.29)		.46
Information source
	Recommended by health care providers	1		N/A
	Social media posts	0.82 (0.48-1.39)		.19
	Special publicity activities	0.83 (0.43-1.60)		.43
	Other	1.28 (0.67-2.43)		.13
Type of smoker
	Cigarette	1		N/A
	Other	1.11 (0.21-6.07)		.90
Tobacco dependence
	Yes	1		N/A
	No	1.64 (1.08-2.51)		.02
Degree of tobacco dependence
	Light	1		N/A
	Medium	0.96 (0.52-1.78)		.14
	Heavy	0.16 (0.02-0.98)		.05
Duration to first cigarette after waking (minutes)
	≤5	1		N/A
	6-30	0.96 (0.62-1.47)		.22
	31-60	1.27 (0.74-2.16)		.49
	>60	1.33 (0.79-2.25)		.30
Hardest cigarette to give up
	First one in the morning	1		N/A
	Other	1.27 (0.88-1.84)		0.20
Reasons for quitting
	Worried about the impact on children	1		N/A
	Prevention of related diseases	1.23 (0.79-1.92)		.55
	Family or friends want me to stop smoking	0.85 (0.44-1.62)		.37
	Other	1.23 (0.79-1.91)		.30

^aN/A: not applicable.