New Study Concludes That Youth E-Cig Use “May Encourage” Smoking… with No Supporting Evidence Whatsoever

By Lindsay Fox Posted March 21, 2014

E-cig use by teen vaper


Research is a pain in the ass. You see, you might want to just skip to the fun part – the part where you get to convince newspapers to publish headlines like “Teens Who Try E-Cigarettes Are More Likely To Try Tobacco, Too” – but there’s this entire evidence thing that has a habit of getting in the way, especially if the thing you want to conclude isn’t likely. If you’re a good (or at least respectable) scientist, you’ll begrudgingly be honest about the conclusions you can realistically draw from the research when you’re reporting your findings to the media. If you’re Stanton Glantz and Lauren Dutra, the lead authors of a new study on youth e-cig use, you’ll take the other option: to hell with what we can fairly conclude, let’s just go ahead and say e-cigs “may encourage” conventional cigarette use among youth anyway.




  • Researchers used the National Youth Tobacco Survey data from 2011 and 2012 to investigate the link between vaping and smoking among US teens.
  • The study was cross-sectional, and so was unable to establish a “cause and effect” relationship, despite the researchers implying that e-cig use leads to increased chances of smoking and not the other way around.
  • Teens who’d smoked over 100 cigarettes or currently smoked were more likely to use e-cigarettes.
  • In 2011, smokers who used e-cigs were more likely to want to quit smoking.
  • The study found that out of teens who’d either had one or more puffs on a cigarette (experimenters) and those who’d smoked 100 cigarettes or more (ever smokers), those who had used or currently used e-cigarettes were less likely to have quit smoking before the survey.
  • However, the cross sectional nature of the study means that it’s unclear whether continued smoking came after the decision to vape or before it; and it seems much more plausible that vaping would follow continued smoking.
  • All that can realistically be determined from this study is that teens who vaped were more likely to be smokers. Correlation doesn’t equal causation, so it’s impossible to say that vaping leads to smoking, as the researchers are insinuating, based on this finding.


The Study – What’s the Relationship Between Vaping and Smoking?


Vaping and smoking


The basic aim of the study was stated as being to examine e-cigarette and conventional cigarette use among large samples from the 2011 and 2012 National Youth Tobacco Survey (17,353 and 22,529, respectively). Effectively, the researchers looked at e-cigarette use (either “current” or ever in the past) and its relationship to ever or current smoking and the intention to quit. The research was cross-sectional, meaning that the data only provides information about a single point in time, and as such can’t establish a timeline of events for any participants or a cause and effect relationship.


The National Youth Tobacco Survey was also the source of the data for the misleading CDC finding that youth e-cig use doubled from 2011 to 2012. The problem with this finding was that the definition of “current” e-cig user in the survey was anybody who had used an e-cig at any point in the previous 30 days; a clearly misleading definition (realistically it should be referred to as recent experimentation). In addition, they failed to report how the vast majority of respondents who’d vaped were smokers, a finding that would be expected given that it’s a product designed for smokers.


In short, this new piece of research uses the National Youth Tobacco Survey data from 2011 and 2012 to perform an extremely similar study to the one conducted in Korea which Glantz released in late December. There too, it was reported that e-cig use may lead to “a new route to smoking addiction in adolescents,” despite the cross-sectional nature of the study.


What They Found – The Vast Majority of Vapers are Smokers


The stated findings don’t look good for e-cigarettes, especially if you’re unaware of the limitations of cross-sectional research or you made the mistake of first reading the news reporting or the press release explaining the findings. The release opens “E-cigarettes, promoted as a way to quit regular cigarettes, may actually be a new route to conventional smoking and nicotine addiction for teenagers, according to a new UC San Francisco study.”


So what did they actually find? Firstly, among those who’d ever had one or more puffs of a cigarette (“experimenters”), e-cigarette use was associated with having smoked 100 or more cigarettes in the past or being a current smoker. Being a “current” vaper was strongly associated with having ever smoked cigarettes (vaping respondents were over 7 times more likely to be smokers) and even more so with current cigarette smoking (almost 8 times more likely among vapers). From this, it is clear that vapers were considerably more likely to be smokers. The research reveals a strong association between the two, but has insufficient information to say that vaping led to smoking or vice-versa. They admit this in the paper themselves:


“The cross-sectional nature of our study does not allow us to identify whether most youths are initiating smoking with conventional cigarettes and then moving on to (usually dual use of) e-cigarettes or vice versa…”


As for the relationship between quitting smoking and vaping, the research turned up several findings which initially appear to support the notion that e-cigs somehow undermine quitting. The results show that among those who’d smoked one puff of a cigarette or more (the experimenters), ever using e-cigs was associated with lower rates of abstinence from smoking for the previous 30 days, six months or year. For this same group, current e-cig use was also associated with lower abstinence rates. Among ever smokers (who’d consumed 100 cigarettes or more previously), ever or current e-cigarette use was also associated with lower rates of abstinence from smoking for all three lengths of time. Additionally, the researchers found that in 2011, current smokers who’d used an e-cigarette were more likely to intend to quit in the following year.


Do E-Cigarettes Undermine Quitting Smoking?


Teen girl vaping e-cigs
Photo credit:


The collection of findings above definitely appears to support the notion – argued in the conclusion to the paper: that “e-cigarette use is aggravating rather than ameliorating the tobacco epidemic among youths.” After all, among those who’d smoked anything from a single puff to more than 100 cigarettes in their life, the ones who’d used e-cigarettes were less likely to have been abstinent from smoking in the time preceding the survey.


The problem with this is that correlation does not equal causation. If you were to break the findings from this research down into a single sentence, it would be “those who use e-cigarettes are more likely to be smokers.” It could be that e-cigarette use leads to smoking, or it could be (the much more plausible suggestion) that continuing smokers are more likely to try e-cigarettes. The researchers acknowledge this uncertainty, but still claim e-cigs are the problem rather than a potential solution. Additionally, the findings which suggest e-cigs undermine quitting are actually just another way of saying the same thing.


Let’s look at the claim that “experimenters” (over one puff of a cigarette in their life) with smoking who used e-cigarettes (either ever or currently) were less likely to have quit smoking. This appears to suggest that kids who smoke a single cigarette but then vape are more likely to then continue smoking as a result. In fact, the cross-sectional nature of the research means that this assumption is unjustified, because it’s unclear whether the continued smoking came before or after the decision to vape.


If you’ve puffed on a cigarette at least once, you either don’t do it anymore or carry on. If you don’t do it anymore, you’d be placed into the “experimenter with cigarettes but now abstinent” group, and chances are – after a single puff of a cigarette that obviously didn’t do much for you – you wouldn’t have much interest in trying vaping. You’d then become a cigarette experimenter who didn’t use e-cigs and is now abstinent. If you did enjoy smoking at first and kept doing it, then you might eventually decide to try vaping. It might work for you, or it might not, so you might become a dual user, quit smoking entirely in favor of vaping or continue smoking because you didn’t enjoy vaping. The core point is that it’s reasonable to assume that if you continued to smoke after experimenting, you’re more likely to then try vaping. So is it really surprising that the experimenters who took that step and decided to vape were less likely to have stopped smoking at the time of the survey than the ones who’d just had as little as a single puff on a cigarette without ever vaping?


Not at all, because we’ve already established that vapers are more likely to be smokers in the first place. It’s portrayed as suggesting that people who’d smoked but didn’t use e-cigs found it easier to quit smoking, but in reality it probably just means that those who only tried smoking once or twice didn’t get to the stage where they’d try vaping in the first place. It doesn’t mean that e-cigs stopped people from quitting; it means that those who kept smoking after experimenting were more likely to try using e-cigs at a later date.


The same basic argument holds for the “ever” smokers. All of these findings can be summarized as “at the point of the survey, non-smokers were less likely to be using e-cigs than smokers.” Of course, that doesn’t translate into scary headlines or feed Stanton Glantz’s anti-e-cig dogma, so that’s not what we heard. So instead, he not only equated correlation with causation, he actually chose the direction he wanted it to go in too. It’s much more reasonable to say that continuing smokers were more likely to try vaping than the non-smokers or ones who tried smoking but didn’t enjoy it, but he went with “vaping prevents people from quitting smoking” instead. For no reason whatsoever.




This is another example of why, in an ideal world, researchers like Stanton Glantz should not be given money to perform studies. What he is being paid to do is create propaganda, disguised by the appearance of scientific experimentation and carefully pitched to the news media so the core messages are broadcast loud and clear. A “most teenage e-cig users are smokers” finding has been transformed into “e-cigarettes lead teens into lifelong smoking addiction,” and that’s the message most people will hear. I’d like to say that it won’t work, but something tells me that for many law-makers and much of the public, that’s just wishful thinking.