How adolescent tobacco use has responded to state tobacco 21 laws and flavor restrictions.

Background: Tobacco 21 (T21) laws (prohibiting tobacco sales under age 21) and flavor restrictions have recently been enacted, yet little is known about the extent to which these policies shifted adolescent tobacco use.Objectives: To examine the associations between state-level T21 laws and flavor restrictions with adolescent tobacco use overall and by age.Methods: We linked state-level T21 laws and flavor restrictions with individual-level data on self-reported levels of cigarette, cigar, and electronic nicotine delivery systems (ENDS) use among 979,477 (500,205 female/479,272 male) 14-18+-year-olds from the 2011-2021 Youth Risk Behavior Surveys. We estimated adjusted zero-inflated negative binomial regression models to predict the likelihood of zero use and frequency of use among users and calculated total predicted use, with year and state fixed effects.Results: There were no associations between flavor restrictions and cigarette, cigar, or ENDS use. There also were no associations between T21 laws and cigarette use; however, when categorized based on the laws' policy components, strong T21 laws were associated with lower cigarette use (total marginal effect estimate: -0.34; -0.59, -0.09; p = .009, showing a 0.34 day/month decline). T21 laws were associated with higher ENDS use (total marginal effect estimate: 0.36; 0.11, 0.60; p = .004, showing a 0.36 day/month increase). Policy effects did not vary by age.Conclusion: Current state policies aimed at reducing access to tobacco products have not curbed adolescent tobacco use. Our findings suggest that more comprehensive state laws, including T21 laws with strong policy components, are needed to fill gaps in federal age and flavor restrictions.