Local Flavored Tobacco Bans and Youth Electronic Nicotine Delivery Systems Use

Importance: Although electronic nicotine delivery systems (ENDS) use is decreasing among youth in the US, the frequency of use is increasing among current users, particularly high school students. Objective: To evaluate the effectiveness of local flavored tobacco ban policies and assess whether policies may have unintended outcomes in youth in California. Design, Setting, and Participants: Repeated cross-sectional study using a confounder-adjusted dynamic difference-in-difference (DID) analysis to obtain estimates of the average treatment effect among the treated (ATT) over 6 years. Participants were middle school and high school students in the 2017-2022 California Healthy Kids Survey. Data were analyzed from February 1 to October 1, 2025. Exposures: Policy exposure (treated group) defined as attending a school in person within a jurisdiction with an active flavored tobacco ban at the time of survey administration. Main Outcomes and Measures: The primary outcome was current ENDS use, and the secondary outcome was current cigarette use. To address confounding, additional measures included racial and ethnic diversity, federal poverty level, and educational attainment, which were aggregated to the local policy jurisdiction area. Results: Among 2 805 708 middle and high school student tobacco users, local flavored tobacco bans were associated with a reduction in current ENDS use of 2.4 percentage points (ATT, -0.024; 95% CI, -0.031 to -0.017) and were not associated with current cigarette use (ATT, 0.002; 95% CI, -0.002 to 0.005). Three years after policy implementation, ENDS use was lower in jurisdictions with flavor ban compared with jurisdictions without by 1.9 percentage points (ATT, -0.019; 95% CI, -0.027 to -0.010). Four years after policy implementation, ENDS use was lower in jurisdictions with flavor ban compared with jurisdictions without by 9.3 percentage points (ATT, -0.093; 95% CI, -0.117 to -0.069). Conclusions and Relevance: In this study, a local flavored tobacco ban policy was associated with reduced ENDS use among youth but not with cigarette use within this population. Future research should also examine trends in other states to evaluate policy adoption and enforcement.