Predictors of Smokeless Tobacco Susceptibility, Initiation, and Progression Over Time Among Adolescents in a Rural Cohort.

Background: Use of smokeless tobacco (ST, moist snuff and chewing tobacco) is elevated among male rural youth, particularly participants in certain sports, including baseball. Objectives: This study aimed to assess factors associated with adolescent male athletes' ST-related behaviors over time, including: baseline use, initiation, and progression in use intensity in a school-based longitudinal cohort. Methods: Baseline and one-year follow-up questionnaires assessed sociodemographic characteristics, environmental factors, and tobacco-related perceptions and behaviors among 9- to12th-grade interscholastic baseball players in 36 rural California schools. Population characteristics were compared among ST use categories (never, experimental, and experienced users). Multivariable models using generalized estimating equations were estimated for outcomes among baseline ST never-users (ST susceptibility and future initiation) and experimenters (ST expectations and progression in ST use). Results: Of 594 participants, over half (57%) had ever tried a tobacco product and the most common products tried were ST (36%) and electronic cigarettes (36%). Being older, perceiving less ST harm, being Non-Hispanic White, using alcohol or other tobacco products, having family or friends who use ST, and being receptive to advertising were associated with greater baseline ST use. Baseline alcohol consumption, lower perceived ST harm, peer use, and susceptibility and expectations were predictive of ST initiation and/or progression at one-year follow-up. Conclusion/Importance: Certain environmental, socio-demographic, cognitive, and behavioral factors predict ST susceptibility and later initiation and progression in use. Interventions addressing these factors have potential to prevent ST uptake and continued use within this high-risk adolescent population.