Differential impact of the Canadian point-of-sale tobacco display bans on quit attempts and smoking cessation outcomes by sex, income and education: longitudinal findings from the ITC Canada Survey

Significance This study examines the differential effects of Canadian point-of-sale (POS) tobacco display bans across provinces on quit attempts and smoking cessation, by sex, education and income. Methods We analysed survey data from five waves (waves 4-8) of the International Tobacco Control Canada Survey, a population-based, longitudinal survey, where provinces implemented display bans between 2004 and 2010. Primary outcomes were quit attempts and successful cessation. We used generalised estimating equation Poisson regression models to estimate associations between living in a province with or without a POS ban (with a 24-month threshold) and smoking outcomes. We tested whether these associations varied by sex, education and income by including interaction terms. Results Across survey waves, the percentage of participants in provinces with POS bans established for more than 24 months increased from 5.0% to 95.8%. There was no association between POS bans and quit attempts for provinces with bans in place for 0-24 months or more than 24 months, respectively (adjusted relative risk (aRR)=0.99, 95% CI: 0.89 to 1.10; 1.03, 95% CI: 0.88 to 1.20). However, we found a differential impact of POS bans on quit attempts by sex, whereby bans were more effective for women than men for bans of 0-24 months. Participants living in a province with a POS ban for at least 24 months had a higher chance of successful cessation (aRR=1.49; 95% CI: 1.08 to 2.05) compared with those in a province without a ban. We found no differences in the association between POS bans and quit attempts or cessation by education or income, and no differences by sex for cessation. Conclusion POS bans are associated with increased smoking cessation overall and more quit attempts among women than men.