E-cigarette use is associated with subsequent cigarette use among young adult non-smokers, over and above a range of antecedent risk factors: a propensity score analysis.

Introduction:
In this article, you will learn about a study examining the relationship between e-cigarette use among young adult nonsmokers and later use of combustible cigarettes. The study used a pseudo-experimental design with inverse probability weighting to account for potential confounding factors. The results indicate that e-cigarette use among 21-year-olds without a history of previous smoking was associated with a twofold increase in risk of combustible cigarette use two years later, and this relationship was not solely explained by measured preexisting interpersonal, intrapersonal, or demographic factors.

Key Points:

* The study used a pseudo-experimental design with inverse probability weighting to account for potential confounding factors.
* The sample was large, diverse, and had excellent retention, with longitudinal data and a broad range of risk and protective factors included in the IPW analyses.
* The study found that e-cigarette use among 21-year-olds without a history of previous smoking was associated with a twofold increase in risk of combustible cigarette use two years later.
* The relationship between e-cigarette and combustible cigarette use was not solely explained by measured preexisting interpersonal, intrapersonal, or demographic factors.
* The study suggests that as e-cigarette use increases in popularity among adolescents and young adults, there is significant concern that the novelty of the devices coupled with the variety of flavor options may lead nonsmokers to use e-cigarettes, which may lead to nicotine addiction and combustible cigarette use.
* The study highlights the need for interventions aimed at young adults to prevent transition to combustible cigarette smoking.
* Stronger regulations on flavor, internet sales, age limits, and advertising are needed to reduce the appeal of e-cigarettes.

Main Message:
The study provides evidence that e-cigarette use among young adults without a history of previous smoking is associated with an increased risk of combustible cigarette use two years later. This relationship is not solely explained by measured preexisting factors, suggesting that e-cigarettes may have a direct role in leading youth to combustible cigarette use. Therefore, stronger regulations on e-cigarettes are needed to prevent the initiation of nicotine use and reduce the appeal of these products to young people. additionally, interventions aimed at young adults are needed to prevent transition to combustible cigarette smoking, which carries worse health risks than e-cigarette use.

Epstein M, Bailey Ja, Kosterman R, et al. E-cigarette use is associated with subsequent cigarette use among young adult non-smokers, over and above a range of antecedent risk factors: a propensity score analysis. addiction (abingdon, England). 2021;116(5):1224-1232. doi:10.1111/add.15317