PROJECT SUMMARY/ABSTRACT Tobacco use remains the leading cause of preventable death in the United States. Almost 50% of youth tobacco users now concurrently use two or more tobacco products—defined as multiple tobacco product (MTP) use. Youth MTP use is concerning because it associated with a two-fold increase in nicotine dependence symptoms, decreased likelihood of successful quitting, and increased risk of other substance use and mental health problems. Many communication messages exist to warn youth of the harms of specific tobacco products, like e-cigarettes or cigarettes. However, almost all tobacco communication messages focus on one tobacco product at a time, which could lead MTP users to consume the tobacco product that is not the target of the messages. Moreover, these communication messages may not work well with MTP users who are more likely than single tobacco users to underestimate the harms of tobacco, be more dependent on nicotine, and be of lower socioeconomic status (SES). The overarching goal of the proposed K01 project is to develop and evaluate messages about the harms of MTP use. The primary hypothesis is that MTP messages will increase intentions to quit using all tobacco products more than existing messages that focus only on single tobacco products and control messages. A secondary goal is to determine the impact of messages among youth at higher risk of MTP use, specifically youth of lower SES. In Aim 1, I will identify effective themes for youth-oriented messages that communicate the harms of MTP use. In Aim 2, I will develop a set of high impact messages that discourages MTP use among youth and determine whether other message elements (e.g., testimonials, quitting approach, self-efficacy cue) increase tobacco quit intentions using a discrete choice experiment (DCE) with youth MTP users. Finally, in Aim 3, I will conduct a three-arm pilot randomized controlled trial (RCT) with youth MTP users (50% lower SES) to see if the MTP messages delivered as text messages over a two-week period increase tobacco quit intentions more than existing messages that focus only on single tobacco products and control messages. This research would make significant and timely contributions to the development of tobacco control communication strategies in the United States and is responsive to FDA’s interest in communications research. My long-term career goal is to conduct independent research that focuses on preventing and reducing youth tobacco use through health communication interventions. This career development award will help me reach this goal by providing new training in a) health communication theory and message development, b) experimental design for health communication research, including design of discrete choice experiments, and c) eHealth interventions for youth. My training plan includes apprenticeships with my mentorship team, formal coursework, hands-on research activities, and workshops. This award will culminate in a R01 application for a full-scale RCT testing the effectiveness of MTP messages on quit attempts and other behavioral outcomes among youth MTP users.

PROJECT NARRATIVE Multiple tobacco product (MTP) use—or the concurrent use of two or more tobacco products—is the dominant pattern of tobacco use among youth in the United States, however, little research has been conducted on communication messages that could prevent and reduce youth MTP use. Using rigorous and innovate methods, the overarching goal of the proposed research is to develop and evaluate messages about the harms of MTP use. This research would make significant and timely contributions to the development of tobacco control communication strategies in the United States and is responsive to FDA’s interest in communications research.