PROJECT 4 Abstract Tobacco use varies greatly by race/ethnicity and socioeconomic status (SES) in the US, with unacceptably high cigarette smoking rates in American Indian Alaska Native and low education populations, as well as vulnerable subpopulations at the intersection of race/ethnicity and SES (e.g. non-Hispanic Black (NHB) and non-Hispanic White (NHW) individuals with a high school degree or less). Use of cigars and electronic nicotine delivery systems (ENDS) are highest among NHB and NHW individuals respectively. Tobacco use trajectories are further complicated by characterizing flavors in cigarettes (menthol), cigars, and ENDS, the use of which is concentrated in specific subpopulations. Policymakers are considering flavor restriction policies and other tobacco regulations but lack detailed scientific information about how such policies could affect the US population and vulnerable subgroups. To address this need, we will develop validated tobacco simulation models to project the impact of flavor restrictions on tobacco use and downstream health outcomes among vulnerable racial/ethnic and socioeconomic subgroups. While existing simulation models consider cigarette smoking, with some now also assessing ENDS use, cigar smoking has yet to be included in such models, despite its important implications for tobacco-related health disparities. This project aims to characterize cigarette, cigar, and ENDS patterns of use by race/ethnicity, education, and for vulnerable subgroups at their intersection (Aim 1). We will develop simulation models of cigarette, cigar, and ENDS use for (a) key race/ethnicity groups (NHB, NHW, Hispanics and AIAN), (b) four different education groups (less than high school, high school degree or GED, some college, and college degree or more) and (c) for groups at the intersection of race/ethnicity and education (NHB, NHW, Hispanic individuals of low vs. high educational attainment) (Aim 2). We will estimate the effects of flavor restrictions on cigarette, cigar, and ENDS use by race/ethnicity and education using information from quasi-experimental studies, systematic reviews, and expert consultations (Aim 3). Finally, we plan to project the impact of flavor restrictions on US patterns of tobacco product use and downstream mortality outcomes by race/ethnicity and education, and for key vulnerable groups at their intersection (Aim 4). This will provide a strong foundation for studying the impact of other potential regulations on tobacco-related health outcomes in vulnerable subgroups. As part of the Center for the Assessment of the Tobacco Regulations (CAsToR), this project will provide the Food and Drug Administration (FDA) with much needed external modeling research that evaluates: 1) the impact of flavor restrictions on tobacco use behaviors (Scientific domain: Behavior); 2) the long-term impact of tobacco products and flavor restrictions on health (Scientific domain: Health Effects); and 3) the potential differential im...