Trends in noticing and responses to cigarette and heated tobacco product warnings among Koreans who use tobacco: findings from the 2020–2023 ITC Korea Surveys

BACKGROUND: South Korea is the only country to mandate graphic health warnings on both cigarettes and heated tobacco products (HTPs), with updates required every 2 years. Few studies have assessed real-world responses to warnings for HTPs, whose popularity has grown around the world, including in Korea. METHODS: Data were analysed from the 2020, 2021 and 2023 International Tobacco Control Korea Surveys, administered online. Respondents were adults who reported at least weekly use of cigarettes (n=11 280) or HTPs (n=5731). Weighted logistic regression models examined attention (eg, often/very often vs never/rarely/sometimes), cognitive responses (eg, thinking about risks a lot vs a little/not at all) and cessation-related responses (eg, forgoing use vs none) to cigarette and HTP warnings. Each outcome was analysed separately by product use frequency and survey year, adjusting for sociodemographics and quit intentions, with model-implied estimates derived using post-estimation commands. RESULTS: As warnings were updated from 2020 to 2023, attention increased for both products, including noticing warnings for cigarettes (37% to 50%) and HTPs (26% to 50%), but cessation-related responses generally decreased, particularly for HTPs (eg, agreement that warnings make quitting HTPs more likely decreased from 20% to 12%). People who reported weekly use (vs daily use) consistently showed lower attention but higher cessation-related responses for both products. CONCLUSIONS: Despite growing attention to warnings over time, cognitive and cessation-related responses to warnings declined from 2020 to 2023, especially for HTPs. These findings suggest attenuation of warning effects and the potential need to expand the warning content.