Measuring the impact of state and local Tobacco 21 policies in the United States: A longitudinal study of youth and young adults ages 15-21

Introduction: Tobacco 21 (T21) policies, which prohibit tobacco sales to individuals under 21, aim to reduce youth tobacco use by limiting youth access to these products. Little, however, is known about the longitudinal effect of T21 policies on youth tobacco use behaviors at the national level. Methods: Participants aged 15-21 years from a longitudinal study conducted between May 2014 and May 2019 (n=13,990) were matched to geocoded T21 policies. Generalized linear mixed models examined the association of direct and bordering T21 policy exposure and cigarette and e-cigarette use and intention to use, accounting for individual characteristics. Results: Controlling for sociodemographic and psychosocial covariates, there were statistically significant positive associations between T21 exposure and e-cigarette use (OR=1.45 [1.03,2.06], p<.003) and intention to use e-cigarettes (OR=1.54 [1.05,2.26], p<.027). We found no association between T21 policy exposure and cigarette use or intention to use cigarettes. Furthermore, exposure to T21 policies did not significantly modify the relationship between age and either cigarette outcome. Conclusions: This is the first longitudinal study to evaluate state and local T21 policies at the national level. Our analyses demonstrate that existing T21 policies are not sufficient to reduce youth tobacco use and intentions to use, and suggest that T21 policies need to be a part of a comprehensive tobacco policy landscape. Our findings suggest further research is warranted on state and local T21 policy enforcement and implementation, including how T21 may differentially impact cigarette and e-cigarette use, and may have implications for the federal T21 policy. Implications: This research evaluates state and local T21 policies in the United States longitudinally, finding that T21 policies are not sufficient to stem e-cigarette use among adolescents and young adults. These findings support further policy action and suggest that local and state T21 policies are not sufficient to reduce tobacco use and rather, need to be part of a broader, more comprehensive set of tobacco control policies. Further research on enforcement and implementation challenges of T21 policies and the impacts of the new federal T21 policy is warranted.