Adolescent Tobacco Uptake and Other Substance Use: A Latent Class Analysis.

Objective: The purpose of this study was to identify patterns of tobacco uptake and other substance use, from early to late adolescence. Methods: We used weighted latent class analysis, conducted separately for 7th, 9th, and 11th graders, to assess patterns of susceptibility, ever and current use of combustible tobacco and e-cigarettes, and other substance use (ie, current alcohol, binge drinking, and marijuana). Data were from Wave 3 of the Texas Adolescent Tobacco and Marketing Surveillance System (n = 2733; N = 461,069), collected in fall 2015. Multinomial regression was used to examine differences in class membership by demographic factors. Results: Two latent classes were identified in 7th grade, 3 classes in 9th grade, and 4 classes in 11th grade models. In each grade, classes included both a "no risk" and a "tobacco susceptible" class. For 9th grade, there was an additional "tobacco ever use" class, and 11th grade had the same additional class as well as an "all products use" class. Conclusion: Distinct patterns of polysubstance use emerged as grade level increased, supporting a stage-sequential model of onset and progression across developmental age groups. Future research can examine other factors affecting transitions across these stages.