Patterns, clusters, and transitions in U.S. state ENDS policy implementation: 2010-2020.

Electronic nicotine delivery systems (ENDS), such as e-cigarettes, have become increasingly used across the world. To respond to global public health challenges associated with vaping, governments have implemented numerous ENDS policies. This research highlights the patterns, clustering, and transitions in U.S. state ENDS policy implementation from 2010 to 2020. Policy data for tobacco and ENDS policies primarily from the Americans for Nonsmokers' Rights Foundation (ANRF) were analyzed for the years 2010 to 2020 for all fifty states and Washington, D.C. Patterns and clusters of policies were assessed. Latent trajectories were modeled for ENDS policies across states over time. ENDS policies commonly have analogous tobacco control policies in place prior to their implementation. ENDS policies in states were commonly implemented in "bundles." The temporal trajectories of ENDS policy implementation occurred in 3 latent forms. A majority of states were "catch-up implementers," indicating their slow initial implementation but stronger position by the end of the period of observation in 2020. These trajectories of ENDS policies were not associated with any individual tobacco control policy in place at the start of the trajectory in 2010. The development of ENDS policies in U.S. states has been temporally and geographically uneven. Many states that had initially been slow to implement ENDS policies caught up by 2020. The implementation of policy "bundles" was common. The clustering of policies in bundles has important methodological implications for analyses, which should be considered in ENDS policy evaluations.