Table 1.

Analysis of the interaction effect on smoking cessation outcomes at the 6-month follow-up

		Odds ratio (95% CI)	p-value*
Interaction term	Group allocation X Hardcore status
Dependent variable	7-day abstinence	2.81 (0.34, 23.07)	0.34
Dependent variable	Any quit attempt (including quitters)	2.42 (0.67, 8.79)	0.18
Dependent variable	Smoking reduction by at least 50% (including quitters)	0.72 (0.29, 1.84)	0.50
Interaction term	Group allocation X Smokers whose daily cigarette consumption ≥15
Dependent variable	7-day abstinence	0.56 (0.21, 1.53)	0.26
Dependent variable	Any quit attempt (including quitters)	0.73 (0.37, 1.46)	0.38
Dependent variable	Smoking reduction by at least 50% (including quitters)	0.96 (0.46, 1.97)	0.90
Interaction term	Group allocation X Smokers with quit attempt experience
Dependent variable	7-day abstinence	2.15 (0.45, 10.17)	0.33
Dependent variable	Any quit attempt (including quitters)	1.34 (0.52, 3.42)	0.54
Dependent variable	Smoking reduction by at least 50% (including quitters)	0.68 (0.29, 1.59)	0.38

*p-value for interaction term: group allocation (intervention versus control) X type of smokers (hardcore versus non-hardcore).