Understanding nicotine pouch adoption and longitudinal use patterns among U.S. adults - ABSTRACT Nicotine pouches are oral, spit-free products that contain nicotine; while they resemble smokeless tobacco (SLT) products, they contain nicotine powder rather than tobacco leaf. Sales of nicotine pouches have skyrocketed in recent years and these products now account for more than 40% of the smokeless market share. Interest in and use of nicotine pouches appears to be greatest among people who use other tobacco products, including cigarettes, e-cigarettes, and SLT. As non-combustible products with no tobacco leaf, no vapor, and no inhalation, nicotine pouches hold potential for harm reduction, and data indicate that nicotine pouches are more similar to medicinal nicotine replacement therapy than to tobacco. Nicotine pouches could have a positive impact on population health if adults use pouches to quit tobacco or switch to exclusive pouch use, provided that tobacco- naïve young people do not initiate regular use; the harm reduction potential for these products is limited if dual or poly product use is the dominant pattern. However, the trajectories of tobacco and nicotine product use among adult tobacco users who have purchased and tried nicotine pouches remains unknown, making it difficult to assess the potential public health impact of these products. Further, there are no studies that investigate detailed nicotine pouch use behavior, contexts of use, and changes over time among adults who use tobacco at the national level. This mixed methods R01 application will employ a nationally representative longitudinal survey study, integrated with qualitative interviews, to advance the scientific understanding of nicotine pouch use at the population level, generally among adults and specifically among those who use other products. Our study will answer important questions about who is using nicotine pouches, reasons for use, methods, frequency, and intensity of use, indicators of dependence, and product characteristics that influence use. Improved knowledge about each of these factors is critical for understanding of the impact of these products on public health. We will conduct a nationally representative 5-wave longitudinal web survey of 500 adults with a history of cigarette, e- cigarette, or SLT use who currently (past month) or recently (past 6 months) used nicotine pouches to characterize people who recently tried or use nicotine pouches and identify predictors of pouch adoption (regular use) and progression to exclusive pouch use (Aim 1). With quarterly data collection, we will examine trajectories of nicotine pouch use, including changes in frequency and intensity of pouch use, use of other products, and nicotine dependence indicators over a 15-month period (Aim 2). We will also evaluate predictors of trajectories and hypothesize that adults who transition to or maintain exclusive nicotine pouch use will exhibit lower nicotine dependence than those who use multiple products. Finally, we will conduct semi-structured interviews with a subset of survey participants at 3 time points to gain deeper understanding of how users differentiate various oral tobacco and nicotine products, reasons for trying oral nicotine, reasons for continuing (or discontinuing) pouch use, methods of pouch use, and perceptions about product brands and characteristics (Aim 3).
