New UCSF study: E-Cigarettes are Expanding Tobacco Product Use Among Youth

Lauren Dutra and I just published “E-cigarettes and National Adolescent Cigarette Use: 2004–2014” in Pediatrics.  Here is the press release that UCSF issued on it:

 

E-Cigarettes are Expanding Tobacco Product Use Among Youth 

First National Analysis Shows E-Cigarettes Attract Low-Risk Adolescents Who Were Unlikely to Start Smoking

 

E-cigarettes – thought by some to be responsible for a decline in youth cigarette smoking – are actually attracting a new population of adolescents who might not otherwise have smoked tobacco products, according to a new UC San Francisco study.
 
In the first national analysis of the impact of e-cigarettes on trends in youth smoking in the United States, UCSF researchers did not find evidence that e-cigarettes have caused youth smoking to decline. In fact, combined e-cigarette and cigarette use among adolescents in 2014 was higher than total cigarette use in 2009, according to the study.
                 
The authors concluded that the low-risk youth in the study, who went on to smoke regular cigarettes, may not have used nicotine at all if e-cigarettes did not exist.
 
The study will be published online January 23, 2017 in Pediatrics as well as the February print issue of the journal.
 
“We didn’t find any evidence that e-cigarettes are causing youth smoking to decline,” said lead author Lauren Dutra, a former postdoctoral fellow at the UCSF Center for Tobacco Control Research and Education and current social scientist at RTI International, a not-for-profit research organization based in North Carolina.
 
“While some of the kids using e-cigarettes were also smoking cigarettes, we found that kids who were at low risk of starting nicotine with cigarettes were using e-cigarettes,” Dutra said. “Recent declines in youth smoking are likely due to tobacco control efforts, not to e-cigarettes.”
 
The national analysis builds on several previous studies that have reported that adolescents who start with e-cigarettes are more likely to subsequently smoke traditional cigarettes.
 
In August 2016, the U.S. Food and Drug Administration restricted e-cigarette purchases to adults ages 18 and older (California set the age to 21). The FDA also will require a warning label on e-cigarettes, starting August 2018, regarding the addictive nature of nicotine. However, the FDA’s ruling does not regulate advertising or flavors, and e-cigarettes continue to be sold in flavors that appeal to youth.
 
In the new UCSF study, the researchers examined survey data from more than 140,000 middle and high school students who completed the CDC’s National Youth Tobacco Survey between 2004 and 2014.
 
The authors found that cigarette smoking among U.S. adolescents declined during that decade, but did not decline faster after the advent of e-cigarettes in the U.S. between 2007 and 2009.
 
The authors also performed an in-depth analysis of the psychosocial characteristics of e-cigarette users. Research has established that smokers tend to display certain characteristics that non-smokers are less likely to show, such as a tendency to live with a smoker or to wear clothing that displays a tobacco product logo. The smokers in the national youth survey displayed these characteristics, but the adolescents who were only using e-cigarettes displayed few of these qualities.
 
“E-cigarettes are encouraging – not discouraging – youth to smoke and to consume nicotine, and are expanding the tobacco market,” said senior author Stanton A. Glantz, PhD, UCSF professor of medicine and director of the UCSF Center for Tobacco Control Research and Education.
 
The new results are consistent with a similar study of youth in California conducted last year by researchers at the University of Southern California and also published in Pediatrics. Those researchers also found that adolescents who used e-cigarettes – but not cigarettes – displayed few of the risk factors commonly found among cigarette smokers.
 
In combination, the two studies suggest that “e-cigarettes are attracting low-risk youth,” the UCSF scientists said.
 
The research was funded by the National Cancer Institute (grants CA-113710, CA-060121, and CA-180890).
 
The UCSF Center for Tobacco Control Research and Education specializes in tobacco control research focused on policy change, smoking cessation, nicotine addiction, health disparities in smoking, novel tobacco devices and tobacco marketing. It also houses the Truth Tobacco Documents Library, a rich resource of previously confidential tobacco industry documents.
 

 
Here is the abstract:
 
BACKGROUND: E-cigarette use is rapidly increasing among adolescents in the United States, with some suggesting that e-cigarettes are the cause of declining youth cigarette smoking. We hypothesized that the decline in youth smoking changed after e-cigarettes arrived on the US market in 2007.
METHODS: Data were collected by using cross-sectional, nationally representative school-based samples of sixth- through 12th-graders from 2004–2014 National Youth Tobacco Surveys (samples ranged from 16 614 in 2013 to 25 324 in 2004). Analyses were conducted by using interrupted time series of ever (≥1 puff) and current (last 30 days) cigarette smoking. Logistic regression was used to identify psychosocial risk factors associated with cigarette smoking in the 2004–2009 samples; this model was then applied to estimate the probability of cigarette smoking among cigarette smokers and e-cigarette users in the 2011–2014 samples.
RESULTS: Youth cigarette smoking decreased linearly between 2004 and 2014 (P = .009 for ever smoking and P = .05 for current smoking), with no significant change in this trend after 2009 (P = .57 and .23). Based on the psychosocial model of smoking, including demographic characteristics, willingness to wear clothing with a tobacco logo, living with a smoker, likelihood of smoking in the next year, likelihood of smoking cigarettes from a friend, and use of tobacco products other than cigarettes or e-cigarettes, the model categorized <25% of current e-cigarette–only users (between 11.0% in 2012 and 23.1% in 2013) as current smokers.
CONCLUSIONS: The introduction of e-cigarettes was not associated with a change in the linear decline in cigarette smoking among youth. E-cigarette–only users would be unlikely to have initiated tobacco product use with cigarettes.

The full citation for the paper is:  Dutra LM and Glantz SA. E-cigarettes and National Adolescent Cigarette Use: 2004–2014. Pediatrics. 2017;139(2):e20162450.  The full paper is available here.