Vape study denies 'gateway'
A British study has found young vapers are less likely to try cigarettes later.
The observed ‘gateway’ effect of e-cigarette use among teens is “likely to be small,” with only a tiny proportion of experimental vapers going on to smoke regular cigarettes, suggests new research.
If anything, young vapers are less likely to go on to smoke regular cigarettes than their peers who try out other tobacco products first, the findings indicate.
The potential ‘gateway’ impact of e-cigarettes on teen smoking uptake has been hotly contested. Several studies have linked teen vaping to a heightened risk of smoking.
However, most of these studies have looked only at initial uptake, and not continued use, say the researchers.
To try and produce a more nuanced analysis of the issues, researchers compared first experimentation with different types of tobacco products among nearly 40,000 US teens, using responses to the National Youth Tobacco Survey for 2014-17.
The teens were asked if they had ever tried a cigarette, even if it was only a puff or two. Those who said yes, were classified as ‘ever smokers’; those who had smoked at least one cigarette in the past 30 days were classified as such; while those who had smoked more than 100 cigarettes to date were classified as ‘established smokers’.
Teens in each of these groups who had tried e-cigarettes first were compared with those who had first used other combustible tobacco products, such as cigars, cigarillos, hookahs, or pipes, and those who had first used non-combustible tobacco products, such as snuff and chewing tobacco.
The three groups of smokers who had first tried e-cigarettes were then matched with teens with similar social, demographic, and behavioural characteristics, including vulnerability to taking up smoking, but who had not tried e-cigarettes first.
This was done using a statistical technique that mimics some of the features of a clinical trial and reduces the influence of other outside factors.
The most common ‘starter’ product was cigarettes, the findings showed, followed by other combustibles, e-cigarettes, and non-combustibles.
Compared with those who first used tobacco alternatives to cigarettes, those who first tried e-cigarettes were less likely to have ever smoked cigarettes.
Less than 1 per cent of teens who tried e-cigarettes became established smokers, a proportion that was significantly smaller than any other category.
The conversion rate from ever to established smoking was much lower for teens who tried e-cigarettes first: 2.7 per cent, compared with 9 per cent for combustible product first timers and almost 16 per cent for non-combustible product first timers.
“The association of subsequent use of e-cigarettes was stronger for adolescents initiating with cigarettes than the association of subsequent cigarette smoking for e-cigarette initiators,” wrote the researchers.
“This underlines the fact that cigarettes act as a much more important gateway for any product use,” they explain.
“Over the time period considered, e-cigarettes were unlikely to have acted as an important gateway towards cigarette smoking, and may, in fact, have acted as a gateway away from smoking for vulnerable adolescents….The postulated gateway effect is likely to be small.”