Dual trajectories of cigarette smoking and smokeless tobacco use from adolescence to midlife among males in a midwestern US community sample

Introduction: Identifying trajectories of tobacco use is critical for understanding its natural history and targeting interventions, but research on trajectories of smokeless tobacco and dual use of smokeless tobacco and cigarettes is very limited. This study identified tobacco use trajectories from adolescence to midlife and tested correlates of trajectory group membership. Methods: This study included all male participants in a longitudinal study who reported cigarette smoking or smokeless tobacco use in 1987, 1993, 1999, 2005, or 2011 (N = 2230). Group-based trajectory analyses were conducted with zero-inflated Poisson models. Analysis of covariance was used to test adolescent health beliefs associated with trajectory group membership. Results: Five smoking trajectory groups were identified: (1) consistent abstinence from cigarettes; (2) late onset intermittent, then cessation; (3) early onset regular, then cessation; (4) delayed onset regular, then cessation; and (5) consistent regular. Four smokeless tobacco trajectory groups were identified: (1) early onset, then cessation; (2) consistent abstinence from smokeless tobacco; (3) late onset, escalating; and (4) consistent regular. The proportion of participants in trajectory groups representing dual use was low. Adolescent beliefs favorable to smoking and smokeless tobacco were associated with membership in consistent regular use groups. Conclusions: The prevalence of dual use of cigarettes and smokeless tobacco was low, and there was little evidence to suggest switching between tobacco products. Participants who held more positive beliefs about smoking and smokeless tobacco as adolescents were more likely to be consistent regular users of cigarettes and smokeless tobacco into adulthood.