Electronic Cigarette Use and Smoking During Early Adolescence

[ Music ]>>The JAMA Network. [ Silence ]>>Hi. I’m Adam Leventhal, Associate
Professor and Director of the Health, Emotion, and Addiction Laboratory within
the Keck School of Medicine at the University of Southern California. E-cigarettes are battery-powered
devices which heat up a solution that usually contains nicotine
and some other chemicals into an aerosol that can be inhaled by the user. The major intended purpose of e-cigarettes,
initially, were to help adult smokers who were looking for a way to back alternative. And e-cigarettes could potentially help
them cut down or even quit smoking. There’s also a corresponding evolution
in the popularity of e-cigarettes such that were seeing quite an
extensive increase in the use of e-cigarettes nationally among teens
primarily for recreational purposes. So even teens who have never even smoked
before, a lot of them are using e-cigarettes. If they use e-cigarettes and they enjoyed
the experience of inhaling nicotine, it’s possible that they might be more
open to trying other tobacco products like conventional cigarettes and
other smokable tobacco products. And of course, that’s a major
public health concern. So the objective of this
study was to see whether teens who use e-cigarettes are more likely
to start smoking than teens who don’t. We partnered with 10 schools in the Los
Angeles Metropolitan Area, and back in 2013, we invited all teens who were
enrolled in those schools who were ninth graders to complete surveys. We selected 2530 of them who reported that they had never tried any smokable tobacco
product at the beginning of ninth grade. And we followed that group. We came back and gave them another survey
six months later at the end of ninth grade. And then a third survey a year later. And the primary aim was to compare the teens
who had used e-cigarettes to those who hadn’t at the beginning of ninth grade in
terms of the likelihood of starting to smoke a combustible tobacco product
over that 12-month follow-up period. The teens who used e-cigarettes were more
than 4 times more likely to start smoking over the follow-up period than the
teens who didn’t use e-cigarettes. This was consistent over every
tobacco product we studied. And we looked at a number of factors that
could potentially account for this association as co-variants in the study,
including demographic factors. We also looked at personality
traits like impulsive tendencies. We also asked questions like, ‘Do you think that
you’ll start smoking over the next six months? Or, ‘If your friends offered you a
cigarette, would you be willing to try it?’ And, even we statistically accounted for all
of those factors that are known risk factors for smoking initiation, we still found
consistent associations between e-cigarette use and the likelihood of starting smoking. So while we found consistent associations,
because this is an observational study, we can’t conclude that there
is a causal effect here. In other words, we can’t conclude that e-cigarette use directly
leads to smoking initiation. But what we can say is there is an
association, and we need to follow this up with future studies to see whether
this association may indeed be causal. And a remaining question is whether e-cigarette
use is associated with the propensity to become a regular, heavy smoker who,
perhaps, is addicted to tobacco cigarettes and other combustible tobacco products. One of the things that we like to
do is develop prevention programs that can educate teens about, you know,
what are in these e-cigarette products and what are the potential consequences. And if we could do that, we potentially
could have some really important downstream consequences for public health and
preventing smoking-related disease.