Project Abstract This application is being submitted in response to the Notice of Special Interest (NOSI) identified as NOT-CA- 20-039. Smokers commonly report co-use with alcohol, and linkages between alcohol use and tobacco use are well-established at multiple levels in the research literature. Tobacco is often used concurrently while drinking alcohol, which influences subsequent co-use behaviors and transitions. For instance, smoking quit attempts are less likely to be successful in the context of alcohol use, and policies targeting use of one product have shown spillover effects on use of the other. However, there has been limited research on the co-use of electronic nicotine delivery systems (ENDS) or heated tobacco products (HTP) and alcohol, and whether alcohol use patterns, including co-use with tobacco, influences tobacco use trajectories and outcomes among smokers who use ENDS. It is similarly unclear how regulatory policies for ENDS and HTPs affect alcohol use. The objective of this project is to provide timely evidence on patterns of tobacco and alcohol co-use among smokers who use ENDS or HTP; how these patterns affect smokers’ decisions to reject ENDS/HTP, substitute them for only a few cigarettes, switch exclusively to them, or use them to completely quit using tobacco; and evaluate how excise taxes and tobacco use restrictions in restaurants and bars affect stated preferences for alcohol and impact tobacco and alcohol co-use. Guided by our prior research, our Aim 1 will examine alcohol and tobacco co-use behaviors among dual users of cigarettes and ENDS/HTP and test whether alcohol-tobacco co-use affects tobacco use transition-probabilities and long-term outcomes. Aim 2 will evaluate the impact of excise taxes, tobacco use restrictions in restaurants and bars, and regulations of the availability of alcohol flavors in tobacco products on behavioral outcomes including tobacco and alcohol co-use and consumption levels. These aims will be accomplished by leveraging the parent grant’s intensive longitudinal study of 300 smokers who recently initiated ENDS or HTP use by adding an additional assessment with a volumetric choice experiment and focus on tobacco and alcohol co-use and by embedding alcohol related questions in existing assessments of the longitudinal study. Data generated by this administrative supplement will provide a more complete understanding of the decision-making processes and factors involved in smokers’ use of ENDS and HTP and the likelihoods that ENDS/HTP use will lead to complete quitting of cigarettes or to sustained dual use, and how the tobacco control policies could have spillover effects on alcohol use. The high impact of this research will be produced by study findings that improve the evidentiary base and quality of local, state, and federal policies and regulations and translatable knowledge that guides future research and clinical practice to encourage less dual use and more switching exclusively from combusted tobacco products to ENDS/HTP or complete cessation of all tobacco products.

Project Narrative Alcohol and tobacco co-use among cigarette smokers who use electronic nicotine delivery systems (ENDS) or heated tobacco products (HTP) may negatively impact health outcomes by increasing the likelihood of continued smoking or dual use of cigarettes and ENDS or HTP. This project will generate data on patterns of tobacco and alcohol co-use among smokers who use ENDS or HTP; how these patterns influence smokers’ decisions to substitute ENDS/HTP for only a few cigarettes, switch exclusively to them, or use them to completely quit using cigarettes; and evaluate how excise taxes and tobacco use restrictions in restaurants and bars might impact alcohol and tobacco co-use. The findings of this project will provide policymakers, researchers, and clinicians with information on the role of alcohol use in tobacco outcomes among smokers who dual use ENDS and HTP that could inform local, state, and federal policymaking and guide future research and clinical decisions to reduce the health burdens of tobacco and alcohol use.