Purpose: To identify trajectories of smoking behaviors of a cohort of youth followed through young adulthood from 2000 to 2013. Design: The Minnesota Adolescent Community Cohort study, a population-based cohort study. Setting: Nationwide, originating in the Midwestern United States. Participants: Cohort of youth surveyed for 14 years beginning at ages 12 to 16 (N = 4241 at baseline; 59% recruitment rate). Measures: Main variable of interest was the number of days smoked in the past 30 days. Also included time-varying and time-invariant covariates. Analysis: We utilized growth mixture modeling to group individuals into trajectories over time. Results: We identified 5 distinct trajectories: nonsmokers (59.5%), early-onset regular smokers (14.2%), occasional smokers (11.5%), late-onset regular smokers (9.4%), and quitters (5.3%). Adjusted models showed that early- and late-onset regular smokers (compared to nonsmokers) had lower odds of attending or graduating from a 4-year college (P <.05). Participants in all smoking classes compared to nonsmokers had greater odds of having more close friends who smoked (P <.05). Conclusion: Our results show that individuals in their teens through young adulthood can be classified into 5 smoking trajectories. More people in this age range remained abstainers than found in most previous studies; however, a sizable group was identified as regular smokers by the time they reached young adulthood. Interventions targeted at teens, including those that address social and environmental influences, are clearly still needed to prevent escalation of smoking as they move toward young adulthood.
Bibliographical noteFunding Information:
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by a grant from the National Cancer Institute at the National Institutes of Health (R01-CA086191; Jean L. Forster, PI)
- young adults