Longitudinal trajectories of E-cigarette use among adolescents: a 5-year, multiple cohort study of vaping with and without marijuana.

Introduction:
This text provides a summary of a longitudinal study examining the developmental trajectories of e-cigarette use among adolescents over a five-year period. The study identified and differentiated between stable trajectories of e-cigarette use with and without marijuana (liquid ThC), and investigated sociodemographic differences in these patterns. The study also compared trajectories between cohorts of adolescents in different grade levels.

Key Points:

* The study followed three cohorts of adolescents in the 6th, 8th, and 10th grades over five years, collecting data every six months through an e-cigarette use survey.
* Growth curve models and growth mixture models were used to identify average trajectories of past 30-day e-cigarette use and investigate developmental patterns in these trajectories.
* The study identified stable trajectories of e-cigarette use with and without marijuana, which varied by age of onset, frequency and escalation in use, and substance used.
* With one exception, all trajectories of e-cigarette use escalated with age.
* The most problematic trajectories, corresponding to more frequent use, were observed among the younger cohorts compared to the oldest.
* Sociodemographic differences in trajectories were also investigated, with some variations observed by sex, race/ethnicity, and SES.
* The study suggests that primary prevention efforts to reduce e-cigarette use among adolescents should begin early and be sustained throughout adolescence.

Main Message:
The study highlights the importance of understanding the developmental trajectories of e-cigarette use among adolescents, as stable patterns of use can have negative health consequences. The findings suggest that interventions to prevent the onset and progression of e-cigarette use among adolescents must be targeted early and be sustained over time. additionally, the study emphasizes the need to consider sociodemographic differences in e-cigarette use patterns to ensure that prevention efforts are effective for all adolescents. Overall, the study reinforces the need for continued research and action to address the growing epidemic of e-cigarette use among adolescents.

harrell MB, Chen B, Clendennen SL, et al. Longitudinal trajectories of E-cigarette use among adolescents: a 5-year, multiple cohort study of vaping with and without marijuana. Preventive medicine. 2021;150:106670. doi:10.1016/j.ypmed.2021.106670