Brittney Keller-Hamilton, PhD, MPH, on Adolescent E-Cigarette Use and Smoking Initiation
Adolescent boys who use e-cigarettes are at an increased risk of smoking cigarettes and using smokeless tobacco products later in life, according to the results of a recent study.1
In effort to explore the possible causal association between adolescent e-cigarette use and future tobacco use, the researchers conducted a propensity score matched analysis. Included were 1220 boys aged 11 to 16 years from Ohio, who reported their use every 6 months for 2 years.
To learn more about the study findings, Consultant360 reached out to lead study author Brittney Keller-Hamilton, PhD, MPH, who is a Research Scientist at The Ohio State University Comprehensive Cancer Center.
Consultant360: To begin, could you tell us a bit about how your study objective came about?
Brittney Keller-Hamilton: There were 2 main motivations for this study. First, we were interested in looking at smokeless tobacco use as one of the outcomes because it remains prevalent in rural and Appalachian areas of the United States—particularly among boys and men. Smokeless tobacco carries significant health risks, and identifying whether e-cigarettes were a risk factor for its initiation is important for addressing rural and Appalachian health disparities related to smokeless tobacco use. Second, we were curious about how applying causal inference methods would affect findings. The existing research in this field had employed more traditional methods of observational data analysis, but we wanted to evaluate whether the same associations would hold if we used methods that were closer to running a randomized experiment.
C360: Why did you decide to focus your study on boys aged 11 to 16 years, rather than include girls of a similar age?
BKH: This study was essentially a secondary data analysis of an existing cohort. The cohort was established to assess predictors of cigarette smoking, smokeless tobacco use, and dual use of these products. Because smokeless tobacco use is rare among girls, only boys were included.
C360: Your study indicated that e-cigarette users were more than twice as likely to initiate cigarette smoking and smokeless tobacco use than those who were not e-cigarette users. Is this a result that surprised you, or did you anticipate this?
BKH: Given the associations previously reported, the results related to cigarette smoking were not surprising. I was not sure what we would find when looking at smokeless tobacco use, however. There is a strong cultural component with smokeless tobacco use in Appalachia (where most smokeless tobacco users in our study live), and we did not know how e-cigarette use would fit into that larger context. Additionally, while cigarette smoking and e-cigarette use both involve bringing the product to one’s mouth, inhaling, and exhaling smoke/vapor, using smokeless tobacco is much different.
C360: How will these findings impact how health care providers prevent and manage e-cigarette use among adolescents?
BKH: I think these results and the other studies on this topic are a good first step, as they demonstrate that using e-cigarettes are a unique risk factor for cigarette smoking. Along this line, a good second step would be research to test how to effectively communicate this message to adolescents who might think that they would never start smoking cigarettes. Given the associations we observed between e-cigarette use, cigarette smoking, and smokeless tobacco, it seems that the nicotine dependence that e-cigarette use can engender either makes youth curious about trying other products with nicotine or leads them to seek nicotine from other products. Recently, national media campaigns targeting adolescent e-cigarette use have focused on communicating that nicotine dependence is associated with a loss of control over one’s choices; health care providers reinforcing this message could be a useful approach.
C360: What knowledge gaps remain concerning the relationship between e-cigarette and cigarette use among adolescents? What is the next step for research in this area?
BKH: The biggest question for me, at this point, is whether there are certain characteristics of e-cigarettes that increase the risk of transition to other tobacco products. Due to the longitudinal design necessary to answer this research question, the types of e-cigarettes that were used by participants in our study and the other studies on this topic were largely precursors to JUUL. JUUL and the similar types of e-cigarettes that followed (eg, Puffbar) use a different form of nicotine than earlier-generation e-cigarettes. This different form of nicotine is less harsh, and thus greater concentrations of nicotine can be used in the e-liquids. I am curious about whether adolescents who initiated tobacco use with JUUL or a similar style of e-cigarette are also at increased risk of transitioning to cigarette smoking or smokeless tobacco use. Or, if these new e-cigarette products are so addictive and palatable, do users remain exclusive e-cigarette users instead?