Table 3

 Predictors of quitting by ITC-4 Wave 2 among all baseline current smokers

Entire sampleUSACanadaUKAustralia
n% quitORn% quitORn% quitORn% quitORn% quitOR
Statistically significant interactions exist between country and ever tried to quit within last year variable.
p<0.05 for odds ratios that are underlined.
Outcome expectancy: Based on smokers’ responses to the question: “How much do you think you would benefit from health and other gains if you were to quit smoking permanently in the next 6 months?” Coded: 1: “not at all”, 2: “slightly”, 3: “moderately”, 4: “very much”, and 5: “extremely”.
Self-efficacy: Based on smokers’ responses to the question: “If you decided to give up smoking completely in the next 6 months, how sure are you that you would succeed?” Coded: 1: “not at all sure”, 2: “slightly sure”, 3: “moderately sure”, 4: “very sure”, and 5: “extremely sure”.
Worries about health and QOL: Based on smokers’ responses to the following two questions: (1) “How worried are you, if at all, that smoking will lower your quality of life in the future?”; (2) “How worried are you, if at all, that smoking will damage your health in the future?” Both questions were coded: 1: not at all worried, 2: a little worried, 3: moderately worried, 4: very worried. Here we used the average for the two variables.
Favourable attitudes about smoking: Based on smokers’ responses to the following two questions: (1) “You enjoy smoking too much to give it up”; (2) Smoking is an important part of your life. Both questions were coded: 1: strongly disagree, 2: disagree, 3: neither agree or disagree, 4: agree, and 5: strongly agree. Here we used the average of the two variables.
Overall opinion of smoking: Based on smokers responses to the question of: “What is your overall opinion of smoking?”
Outcome expectancy is highly correlated with worries about health and QOL (Pearson’s correlation coefficient 0.51, p<0.01).
Age at recruitment (years)
    55 and up12938%0.862937%0.562948%0.864679%1.062396%0.87
Highest level of education
    No response4058%1.14748%0.991068%0.991219%1.271048%1.64
Identified majority group
    White/English only55519%Ref9957%Ref140411%Ref16159%Ref15378%Ref
Intention to quit
    No intention16224%Ref3134%Ref2833%Ref5974%Ref4293%Ref
    Plan to quit beyond 6 months23807%1.895056%1.955688%2.276047%1.797037%2.14
    Plan to quit within 6 months157614%3.3829610%3.0953215%3.7334515%3.8240313%3.77
    Plan to quit within 1 month68218%4.1713921%7.5219218%3.7914022%5.6921112%3.16
Tried to quit within last year
Longest time off smoking
    1 week or less10173%0.382123%0.522603%0.482574%0.442882%0.21
    Between 1 week and 6 months19098%0.853657%1.0849711%1.194957%0.675527%0.63
    6 months or more215514%1.5742914%2.5954917%2.1856715%1.6261011%0.85
Heaviness of smoking index
Baseline smoking frequency
    Daily smoker57408%Ref11437%Ref14449%Ref15768%Ref15777%Ref
    Weekly/monthly smoker52022%1.5611023%1.6313127%2.0711017%0.8616920%1.81
Overall opinion of smoking
    Positive or neutral27587%Ref5527%Ref5879%Ref8426%Ref7776%Ref
    Very negative126711%1.242738%0.7436214%0.8527914%1.9735310%1.60
Continuous variables
Outcome expectancy0.900.851.050.900.81
Worries about health and QOL1.020.941.100.841.23
Favourable attitudes about smoking0.921.170.770.901.06
Nagelkerke’s R20.