RESUMEN
INTRODUCTION: In the US, having a 21 minimum legal sales age for tobacco (T21) at the state level may have impacted age verification of cigarette and e-cigarette purchases among U.S. young adults (ages 18-26), before and/or after federal T21 implementation. AIMS AND METHODS: This study examined this by analyzing data from cigarette and/or e-cigarette users (nâ =â 618 and nâ =â 864) in six metropolitan areas in six states. Participants reported frequency of being age verified ("almost always" vs. less frequently) for cigarette and/or e-cigarette purchases across 3 timepoints (ie, wave 1 [w1]: September-December 2018, w2: September-December 2019, and w3: September-December 2020). Multilevel modeling examined time-varying state T21 status and time (reflecting federal T21 implementation) in relation to age verification of cigarette and e-cigarette purchases, respectively. RESULTS: The proportions almost always age verified for cigarette purchases in states with T21 versus without were: W1: 38.5% versus 37.7%, w2: 33.0% versus 39.1%, and w3: 45.4% versus 30.6%. For e-cigarettes, the proportions were: W1: 30.6% versus 40.3%, w2: 42.3% versus 50.5%, and w3: 56.0% versus 58.3%. In multilevel modeling, state T21 status was associated with greater likelihood of age verification for e-cigarettes (aORâ =â 1.67, CIâ =â 1.13 to 2.45), but not for cigarettes. Age verification increased over time for e-cigarettes-both accounting for and not accounting for state T21 status. There were no changes for cigarettes. CONCLUSIONS: State T21 status and time correlated with age verification for e-cigarettes, but not cigarettes. These self-reported age verification data contribute to evidence from compliance checks, indicating that retailers require additional prompts and enforcement to enhance compliance with T21 laws. IMPLICATIONS: Current findings suggest that variations in regulations and gaps in enforcement may hinder the potential impact of increasing the minimum legal sales age, which ultimately may undermine the promise of such policies, specifically with regard to preventing tobacco use among the underage. Therefore, it is crucial to monitor retailer compliance with T21 laws and evaluate their efficacy to increase ID checks, minimize illegal sales, and curb underage use of tobacco. Relatedly, particular attention to enforcement efforts that may promote compliance is warranted.