Evaluation of statewide restrictions on e‐cigarette nicotine strength—United States, 2017–2022

Aims To evaluate statewide policies restricting e‐cigarette nicotine strength. Design A difference‐in‐difference regression analysis was used to compare e‐cigarette sales in states that restrict nicotine strength with states with no restrictions. Because flavor restrictions might affect sales and nicotine strength, states with flavor restrictions were also assessed. Setting and cases United States e‐cigarette retail sales data during January 2017 to March 2022 were licensed from Information Resources Incorporated. States with restrictions included Massachusetts (restricted maximum nicotine strength to 3.5% and nontobacco flavored e‐cigarette sales in December 2019); Utah (restricted nicotine strength to 3.6% in September 2021); and Rhode Island, New York and Washington (restricted nontobacco flavor sales in October 2019, May 2020 and October 2019 to January 2020, respectively). These were compared with data from 34 states with no e‐cigarette nicotine strength or flavor restrictions. Measurements Weighted mean nicotine strength and total unit sales. Total unit sales per 1000 state population were summed into 4‐week periods by state. Models controlled for emergency responses, state demographics, tobacco control policies, time and state fixed effects. Findings Restricting both nicotine strength and flavors in Massachusetts was associated with a 2.04 percentage point (pp) reduction in mean nicotine strength and 86.76‐unit reduction in monthly unit sales per 1000 persons compared with states with no restrictions (all P