More people are likely vaping, and with greater frequency, in the US since 2013-14, suggests a data analysis published online in the journal Tobacco Control.
The proportion of those vaping daily rose by 230%, while vaping among those aged under 21 quadrupled between 2013-14 and 2022-23, the analysis indicates.
Including vaping frequency in surveillance data may contribute to better understanding of vaping's impact on public health, suggest the researchers.
While e-cigarettes can effectively help adults stop smoking, these products also appeal to young people, most of whom have only dabbled in smoking or not smoked at all, they note.
Monitoring of vaping activity is a public health priority in the US, but few data sources capture both adult and young people's vaping trends, including intensity and frequency, they add.
In a bid to plug this knowledge gap, the researchers drew on survey data from the Population Assessment of Tobacco and Health ( PATH ) Study.
They wanted to estimate trends in the total number of vaping days at the population level between 2013–14 (wave 1) and 2022–23 (wave 7), and to estimate the proportion of vaping days by age (12-17 year olds and those aged 18+).
Analysis of the responses over the 10 year period showed vaping days at the population level rose by 183%; vaping over the past 30 days rose by 45%; and daily vaping rose by 230%.
Vaping days among those under the minimum legal age of 21, and who said they had vaped in the past 30 days, more than quadrupled—up by 337% (278% among 12-17 year olds)---over the study period, accounting for 16% of all vaping days in 2022–3.
"Consistent with previous evidence, the most significant increases in the prevalence and frequency of vaping occurred after 2016–18, a period which corresponds with the rise of JUUL and the shift towards e-liquids containing nicotine salts," say the researchers. These salts change the chemistry of vaping aerosol and facilitate inhalation and nicotine intake.
Adult vaping days have continued to increase since the COVID-19 pandemic, largely due to increases in vaping frequency among adults rather than population growth, they say.
This is an observational study, and as such, can't establish cause and effect. The researchers also acknowledge that survey data are subject to recall so may not always be accurate.
"While vaping days increased across all age groups, pronounced increases between 2013–14 and 2022–23 were observed among youth and younger adults, likely influenced by industry marketing that has predominantly targeted young people, as well as increases in the size of the youth population," they write.
Overall, the findings suggest "that, since 2013–14, not only are more individuals in the US vaping, but those who vape are doing so more frequently, consistent with the increase in the prevalence of daily vaping," they add.
And they conclude: "The vaping days measure offers added value by combining how many people are vaping with how frequently they vape. This is particularly relevant given the market-wide trend towards nicotine salt e-liquids and increased frequency of use among those who vape.
"There are also growing concerns about dual use, where individuals engage in both smoking and vaping without fully transitioning away from cigarettes, and the potential for re-initiation of nicotine use among individuals who formerly smoked and were otherwise at low risk of relapse."
