Although there are few studies on the sources of e-cigarettes acquisition [15, 16, 29], this is the first study to utilize national data comprising of both middle and high schoolers in the U.S. Guided by the SEM, as recommended by the NCI , we examined access to e-cigarettes, and association with frequencies of use. We found that the rate of 21-30 days frequency of e-cigarettes use was 24.9% i.e., 1 in 4 respondents were heavy users. This indicates that a significant number of U.S. youth are exposed to nicotine, which affects brain development .
Further, our findings show that e-cigarettes were obtained from interpersonal (family, peers, and other social networks) and mostly from community (retail stores, vape shops, and the internet) sources. This illuminates that youths continue to have access to e-cigarettes despite policies to restrict access . Notably, acquisition of e-cigarettes from community sources significantly increased the frequency of e-cigarette use, while interpersonal sources (social networks) was associated with a lower frequency of use, confirming prior state-level studies on this issue [15–17, 32]. Consistent with policy statements by the American Public Health Association [33, 34] these results buttress the need to enforce state , and federal policies , to restrict youth access to e-cigarettes, while targeting community level factors.
Additionally, this study determined e-cigarette types as organizational level factors within the SEM. We found that e-cigarettes with prefilled pods/cartridges (JUUL) were the most frequently used (21-30 days), supporting the evidence that JUUL is the most popular [37, 38], and most frequently used [2, 39], e-cigarette among U.S. adolescents. This may be due to JUUL’s variety of flavors, users’ belief that it is less harmful, and social influences [18, 40, 41]. Hence, targeting product types for regulation, could mitigate the increasing use of e-cigarettes. Relatedly, policies banning flavors in e-cigarettes by the U.S. Food and Drug Administration , are headed in the right direction. Exposure to e-cigarette advertisements or promotions was also examined at the organizational level. Consistent with prior studies [43, 44], exposure to e-cigarette advertisements or promotions in retail outlets was significantly associated with a higher frequency of e-cigarettes use among middle and high schoolers. Since the Master Settlement Agreement , the retail environment has fostered youths’ exposure to advertisements or promotions, with concomitant ramifications for the product uptake . Similarly, research suggests that youths in the U.S. are highly exposed to e-cigarettes in retail outlets . Thus, it is crucial to enact policies that limit or prevent youth exposure to e-cigarette advertisements within retail outlets.
Finally, at the intrapersonal/individual level of the SEM, we found that males were more likely to use e-cigarettes for 11-20 and 21-30 days, which is consistent with previous studies [47–49]. These results suggest the need for tailoring different (public) health messages for males and females in middle and high schools in the U.S. Further, our results show that being in high school was associated with a higher frequency of e-cigarette use, which confirms findings in prior studies [1, 47, 50] Indeed, reports from the 2020 NYTS reflect that 38.9% of high-school and 20.0% of middle-school students used e-cigarettes for ≥20 days in the past-month . This suggests that high school is a critical phase in the trajectory of e-cigarette use and warrants further research. Lastly, Hispanics, non-Hispanic Blacks, and other races used e-cigarettes less frequently than non-Hispanic Whites. These results are consistent with previous research that found that the prevalence of frequent e-cigarette use was greater among non-Hispanic Whites [47, 51] Hence, more research on racial disparities in e-cigarette use among U.S. youths is needed.
This study has few limitations. Firstly, access to tobacco products, including e-cigarettes, is illegal in some states for people aged <18 years ; therefore, this may have affected the self-reporting of sources of e-cigarettes with the potential of underestimating results. Secondly, data were collected only from middle and high schoolers who attended public/private schools. Hence, our results may not be generalizable to all adolescents in the U.S . Lastly, since this was a cross-sectional study, we cannot establish causation or temporal relationship.