The study found that adolescents were more likely to have used an e-cigarette than a traditional cigarette.
Researchers from the University of Southern California in Los Angeles also found that the adolescents in their study were more likely to use electronic than traditional cigarettes, reflecting rising rates of use of these devices since their introduction in 2007.
And although many public health experts have expressed concern that e-cigarettes could act as a "gateway" for adolescents to traditional cigarettes, 41% of the study participants who had used e-cigarettes reported that they had never smoked traditional cigarettes.
"If you think of e-cigarette and cigarette use as two circles, the overlap isn't as big as expected," states lead author Jessica Barrington-Trimis, a professor in the Department of Preventive Medicine.
Previous studies have demonstrated that e-cigarettes are used more than traditional cigarettes among high school students, while traditional cigarette use decreased from 2011 to 2014.
However, while the impact of psychosocial influences such as parent and peer use and approval on adolescent cigarette use are well documented, the same cannot be said for their impact on e-cigarette use.
To investigate, the researchers analyzed data obtained from the Southern California Children's Health Study, in which a total of 2,084 11th- and 12th-grade students completed surveys about e-cigarette and traditional cigarette use and attitudes around use at home and among friends.
A total of 499 participants (24%) reported having used e-cigarettes during their lifetime. Of these, 200 (9.6%) had used a device in the past 30 days. Considerably fewer reported having smoked traditional cigarettes, with 390 (18.7%) having smoked one during their lifetime and 119 (5.7%) having smoked one in the past 30 days.
The researchers found that e-cigarette use was strongly associated with psychosocial factors pertaining to both electronic and traditional cigarettes. The likelihood of current e-cigarette use was greatest among participants with the most friends also using the devices and with best friends who reacted favorably to e-cigarettes.
Social environments that appeared positive to e-cigarette use were more common than environments positive to traditional cigarettes. Around 91% of e-cigarette users believed that their friends reacted positively to their habit, compared with only 75.6% of traditional cigarette users.
Could e-cigarettes 'renormalize' traditional tobacco products?
Although many participants believed that both electronic and traditional cigarettes were bad for the health, around 14% disagreed that e-cigarettes were unhealthy - including almost half of current users. In comparison, only 1.4% believed the same to be true for traditional cigarettes.
- E-cigarettes do not contain the tobacco or tar that traditional cigarettes do
- E-cigarettes form vapor by heating a liquid solution that typically contains nicotine
- Only e-cigarettes marketed for therapeutic purposes are currently regulated by the US Food and Drug Administration (FDA).
Overall, the authors concluded that product-specific psychosocial factors were more likely to predict e-cigarette use than traditional cigarette use. Reactions categorized as "very friendly" were associated with 37 times the odds of current e-cigarette use, compared with nine times the odds of current traditional cigarette use.
They believe that the less favorable social perceptions and perceptions of the health risk of traditional cigarettes likely reflect both the known health risks associated with smoking and the success of public health campaigns to denormalize the habit.
However, the study found that some common social risk factors are shared by both electronic and traditional cigarettes, with a social environment that perceives e-cigarettes positively strongly associated with the use of both electronic and traditional cigarettes.
"These results raise the possibility that the generally more favorable social perceptions of e-cigarettes could contribute to the 'renormalization' of tobacco products generally," the authors write.
Prof. Barrington-Trimis says there is a lot of concern among the public health community that e-cigarettes may be recruiting a whole new group of people who never smoked cigarettes. However, whether or not this is the case is not a question that the present study can answer.
One aspect of the cross-sectional nature of the study that limits its findings is that it does not distinguish between habitual users of e-cigarettes and those who have merely experimented with the devices.
As a result, the authors conclude that longitudinal studies of adolescents are required to investigate both the long-term health effects of e-cigarette use and to determine whether or not e-cigarettes will lead to the renormalization of traditional cigarettes.
Recently, Medical News Today ran a Spotlight feature investigating whether e-cigarettes are safe.