RESUMO
BACKGROUND AND AIMS: In May 2017, black-and-white text nicotine addiction warning labels ('warnings') and health and safety leaflets ('leaflets') became mandatory for nicotine vaping products (NVPs) in England, in accordance with the European Union's Tobacco Products Directive. We compared changes over time in noticing warnings and leaflets, recall of warnings about nicotine and concerns about using NVP due to noticing warnings in England, compared with Canada, the US and Australia, where no warnings and leaflets were mandated. DESIGN: 19 005 adult (aged 18+) NVP users, smokers and quitters of cigarettes and NVP from the 2016 and 2018 International Tobacco Control Four Country Smoking and Vaping Surveys in England, Canada, the US and Australia, recruited via probability and non-probability sampling. FINDINGS: Noticing warnings increased in England from 4.9% (2016) to 9.4% (2018) (adjusted OR/AOR=1.64, 95% CI=1.15-2.36); this change was larger than changes in Canada (AOR=2.51, 95% CI=1.71-3.69) and the US (AOR=2.22, 95% CI=1.45-3.39). Recall of a nicotine warning increased in England from 86% (2016) to 94.9% (2018) (AOR=5.50, 95% CI=1.57-19.27) but not significantly elsewhere. Noticing leaflets increased in England from 14.6% (2016) to 19.1% (2018) (AOR=1.42, 95% CI=1.15-1.74); this change was larger than in Canada (AOR=1.42, 95% CI=1.12-1.79), the US (AOR=1.55, 95% CI=1.17-2.06) and Australia (AOR=1.51, 95% CI=1.02-2.22). Among those noticing warnings, concern about NVP use did not change significantly between 2016 and 2018 (all countries p>0.081). CONCLUSIONS: Introduction of mandatory NVP warnings and leaflets in England was associated with small increases in noticing them but not with changes in concerns about NVP use.