A new study has found that young vapers in the United States who begin using e-cigarettes after graduating from secondary/high school are likely to progress rapidly to frequent use. While US youths who start vaping during secondary/high school typically take about three years to progress to frequent use, this newly identified group of young adults who start vaping a bit later, after graduation (mean age = 20 years), tend to reach frequent use in about one year. 'Frequent use' is defined as using e-cigarettes on 20 or more of the past 30 days.
These late initiators also reported the highest prevalence of JUUL use as their first device (34.2%) and showed rapid increases in subsequent risks of both the highest levels of vaping frequency and e-cigarette dependence in young adulthood, compared with other participants with different vaping initiation and progression patterns.
The study has just been published in the scientific journal Addiction.
Lead author Dr. Junhan Cho, of the USC Keck School of Medicine, says "We know from existing research that youth who begin vaping early in their mid-teens are at high risk for developing nicotine dependence and are more likely to continue using nicotine products later in life. Our study identified another high-risk group of late initiators who progressed to frequent use much more quickly. Not surprisingly, this 'late initiation/rapid progression' group showed swift increases in the use of nicotine and other substances and exhibited higher rates of e-cigarette dependence in young adulthood compared with other groups in our study.
"The 'late initiation' group also had a higher rate of using JUUL as their first vaping device. This suggests that the rapid progression to frequent use might be connected in some way to the widespread availability and use of JUUL among US youth in 2018-2019.
"The findings of our study suggest that health policies to reduce vaping harms should target early adulthood as well as adolescence."
This study followed over 2,000 students recruited in 2013 from 10 California high schools and followed until 2023. At the start of the study, all participants were in the 9th grade (typically 14-15 years old). They completed surveys about their e-cigarette use every six months during high school (T1-T7), after which they were annually surveyed via web questionnaires across five waves: T8 (Spring 2019) to T12 (Spring 2023) in young adulthood.
The study found four distinct groups of e-cigarette users.
Just over 21% of the study participants fell into the unexpected Young Adulthood/Rapid Progression class. They did not start using e-cigarettes until after high school graduation but progressed to frequent use within 1.2 years.
Almost 14% of participants fell into the Early High School/Gradual Progression class. They started vaping in early secondary/high school and progressed to frequent use in about 3 years, while still in secondary/high school.
A small group (4.3% of participants) fell into the Late High School/Gradual Progression class. They started using e-cigarettes during late secondary/high school years and progressed to frequent use in about 3 years, after leaving secondary/high school.
Sixty percent of participants fell into the Low Initiation Risk/No Progression class. They had a low risk of initiating e-cigarette use and those that did start vaping did not progress to frequent use.
