BACKGROUND: In February 2020, Canada implemented plain packaging without any changes to the size and content of health warning labels (HWLs), which were last updated in 2012 (pictorial HWLs on 75% of the pack front and back). This pre-post evaluation study assessed the impact of plain packaging in Canada on: (1) pack appeal; (2) HWL effectiveness; and (3) support for plain packaging. Additionally, a quasi-experimental design was used to assess the Canadian results relative to two comparator countries: Australia, where plain packaging (with new larger HWLs) was implemented in 2012, and the United States (USA), where plain packaging has not been implemented and the same text warnings have appeared on cigarette packs since 1985.

METHODS: Data are from adult smokers who participated in the 2018 and/or 2020 International Tobacco Control Smoking and Vaping Surveys in Canada (n=4600), Australia (n=1834) and the USA (n=3046). Online surveys were conducted before (February to July 2018) and after (February to June 2020) the implementation of plain packaging in Canada. Adjusted regression analyses were conducted on weighted data.

RESULTS: Plain packaging was associated with a significant increase in the percentage of Canadian smokers who did not like the look of their cigarette pack (2018: 28.6% vs 2020: 44.7%, p<0.001), whereas no change in pack appeal was observed among smokers in Australia and the USA over the same period. Plain packaging was not associated with changes in HWL effectiveness in Canada. Support for plain packaging increased significantly among Canadian smokers (2018: 25.6% vs 2020: 33.7%, p<0.001).

CONCLUSIONS: Plain packaging in Canada substantially reduced pack appeal and increased support for the policy among adult smokers; however, there was no increase in the effectiveness of Canada's 8-year-old HWLs. The impact of plain packaging on health warning effectiveness may depend on the design of the warnings and length of time since implementation.