Table 3

Binomial logistic regression overall and stratified by nicotine dependence level of the hypothetical decision to quit smoking among 1494 Vietnamese adults who smoke cigarettes in response to cigarette pack price and packaging design attributes

	Quit smoking versus continue to smoke (ref)
	Total (n=1494)	Nicotine dependence level†
	Total (n=1494)	Low (n=492)	Medium (n=511)	High (n=491)
	RR (95% CI)‡	RR (95% CI)‡	RR (95% CI)‡	RR (95% CI)‡
Price (VND)
15 000 (ref)	ref	ref	ref	ref
20 000	0.91 (0.81 to 1.02)	0.84 (0.69 to 1.02)	0.84 (0.67 to 1.04)	1.09 (0.90 to 1.31)
30 000	1.20 (1.07 to 1.35)**	1.34 (1.11 to 1.63)**	1.12 (0.90 to 1.39)	1.14 (0.94 to 1.40)
40 000	1.40 (1.23 to 1.58)***	1.46 (1.17 to 1.83)**	1.43 (1.15 to 1.78)**	1.29 (1.04 to 1.61)*
Packaging design
Branded pack, 50% graphic HWL coverage	ref	ref	ref	Ref
Branded pack, 85% graphic HWL coverage	1.30 (1.18 to 1.42)***	1.42 (1.22 to 1.67)***	1.20 (1.00 to 1.44)*	1.28 (1.11 to 1.48)**
Plain pack, 50% graphic HWL coverage	1.34 (1.21 to 1.49)***	1.45 (1.22 to 1.73)***	1.23 (1.02 to 1.48)*	1.38 (1.17 to 1.62)***
Branded pack, no HWL coverage	0.41 (0.35 to 0.48)***	0.44 (0.34 to 0.57)***	0.38 (0.29 to 0.50)***	0.40 (0.30 to 0.53)***

*P<0.05, **p<0.01, ***p<0.001.
†Based on the Heaviness of Smoking Index, which is calculated based on reported time to first cigarette and number of cigarettes smoked per day.
‡Models adjusted for age, sex, income, nicotine dependence (only for unstratified, total sample) and last brand of cigarettes purchased.
HWL, health warning label; ref, reference group; RR, relative risk; VND, Vietnamese dong.