On his blog yesterday, Dr. Stan Glantz announced that there is "more evidence that e-cigarettes inhibit quitting conventional cigarettes."
I was intrigued by this claim because if true, it would discount much of what I have been doing for the past few years (i.e., supporting electronic cigarettes as a bona fide strategy for quitting smoking). Not only is Dr. Glantz arguing that electronic cigarettes are ineffective; he is arguing that they actually inhibit quitting.
So naturally, I was very curious to read the actual study that Dr. Glantz was citing to provide this evidence that electronic cigarettes inhibit quitting.
The study he cited is entitled "Alternative Tobacco Product Use and Smoking Cessation: A National Study."
Here is what Dr. Glantz tells us about the study, which he says provides evidence that electronic cigarettes inhibit smoking cessation: "Ever use of e-cigarettes was not associated with being a successful
quitter (OR 1.09; 95% CI 0.72-1.65) but was associated with being an
unsuccessful quitter (OR=1.78, 95% CI 1.25-2.53) compared to people who
had never tried to quit."
Dr. Glantz concludes that the evidence from this study "adds to the case that the loudly made claims that e-cigs help smokers quit are wrong."
The Rest of the Story
The truth is that this study adds absolutely no evidence about the effectiveness of electronic cigarettes. The study was not designed to examine the effectiveness of electronic cigarettes. In fact, it was simply a cross-sectional study that investigated the prevalence of ever use of e-cigarettes among a sample of current and former smokers.
To determine whether electronic cigarettes are effective for smoking cessation, one would have to study smokers in a longitudinal fashion. You would want to compare a sample of smokers who used electronic cigarettes to try to quit with smokers who did not use electronic cigarettes to try to quit. Ideally, one would randomize smokers into these two groups, and compare the effectiveness of electronic cigarettes with a different approach such as the nicotine patch or gum.
But that's not what this study did at all. It simply measured ever use of electronic cigarettes among smokers and former smokers at a single point in time. The survey provided no information about whether the smokers used electronic cigarettes in an attempt to quit smoking. It provided no information about the timing of their electronic cigarette use. It provided no information about whether they actually used electronic cigarettes regularly or whether they merely tried the product on a single occasion to see what it was like.
Most importantly, because the study is cross-sectional, it cannot tell us which came first. Did electronic cigarettes cause people to be unsuccessful quitters, or is it the case that people use electronic cigarettes because they are having trouble quitting?
In fact, we know from other research that the latter is true. The majority of smokers who try electronic cigarettes are trying these products specifically because they have failed to quit using other means, such as nicotine replacement therapy. So it is in fact no surprising to find that the use of electronic cigarettes is high among people who have not succeeded in quitting smoking.
To be blunt, if one of my students argued in a paper that this study provides evidence that electronic cigarettes inhibit smoking cessation, I couldn't give the paper a passing grade.
In fact, the very authors of the article make it clear that the results of this study cannot be used to infer that electronic cigarettes inhibit smoking cessation. They write:
"Because this was a cross-sectional study, we could not determine whether use of alternative tobacco products resulted in cessation attempts or whether those who were trying to quit--for whatever reason--were using alternative tobacco products. We also could not determine whether use of these products is intended to facilitate quitting and whether use leads to successful quitting. Prospective longitudinal studies should examine whether smokers who use smokeless tobacco are actually more successful at quitting."
More to the Rest of the Story
The story doesn't end here.
In the same blog post, Dr. Glantz cites another study which he argues provides evidence that electronic cigarettes inhibit quitting. According to Dr. Glantz, this study showed "lower quit rates for e-cig users."
The rest of the story is that this study didn't actually measure quit rates among smokers using electronic cigarettes in an attempt to quit smoking. What Dr. Glantz does not reveal is that instead of estimating
cessation rates among a cohort of smokers who made quit attempts using
these products, the study analyzed cessation rates of a large number of
smokers who had previously tried to quit using e-cigarettes but failed,
and then called a quitline because they had failed and wanted to try
Then, they compared the quit rate among these smokers to that among
smokers without such a history of a failed quit attempt using electronic
In other words, this study did not estimate quit rates among smokers
trying to quit using e-cigarettes. Instead, it estimated quit rates
among many smokers who were not using e-cigarettes in their quit attempt
The truth is that many of the electronic cigarette users in the study did not use electronic cigarettes in their quit attempts!
According to data provided in the paper, a full 28% of the sample of
electronic cigarettes did not use these products in their quit attempts.
It should be clear to readers that this study was poorly designed to
investigate the efficacy of electronic cigarettes. The study systematically
sampled a group of quitline callers who were unsuccessful using electronic
cigarettes. These people tried and failed using electronic cigarettes. How do
we know they failed? Because they wouldn’t have had to call the quitline if
they weren’t still smoking. This is clearly a harder core group of smokers and
it is no surprise that their cessation rates were lower after 6-months than the
comparison group. The study tells us nothing about the effectiveness of
electronic cigarettes, other than that they do not work for everyone. Any researcher sincerely interested
in testing the efficacy of electronic cigarettes would not test the research
question in this way. If the tobacco industry conducted precisely this same study in order to
conclude that electronic cigarettes are ineffective as a smoking
cessation tool, we would call it scientific fraud.
Moreover, the authors of this study, like those of the one discussed above, explicitly stated that the results cannot be used to evaluate the effectiveness of electronic cigarettes for smoking cessation and that the study was not designed for that purpose. Concerned that Dr. Glantz was misrepresenting the results of their study, the authors of the study - who are at Alere Wellbeing
- publicly admitted that the study was never intended to assess the
effectiveness of electronic cigarettes and that the data should not be
used for this purpose.
The Alere Wellbeing blog states very clearly: "The recently published article by Dr. Katrina Vickerman and colleagues has been misinterpreted by many who have written about it. It was never intended to assess the effectiveness of the e-cig as a mechanism to quit."
Dr. Vickerman herself explained
that her results do not in any way indicate that electronic cigarettes
are less effective than NRT, stating: "It may be that callers who had
struggled to quit in the past were more
likely to try e-cigarettes as a new method to help them quit. These
callers may have had a more difficult time quitting, regardless
of their e-cigarette use."
This is a study that Dr. Glantz called a "good study" on "the use of e-cigs for cessation."
If this is a "good study" on the use of e-cigs for cessation, I'd like to see a bad one.
As my readers know, Dr. Glantz was and is a hero to me. He was a mentor for my career in tobacco control. He set an example to me for the use of science for advocacy purposes. He still is way ahead of the rest of the tobacco control movement in seeing the field and the direction it needs to go. He has always been the person who I considered to be the leader of the movement. However, it appears to me that Dr. Glantz - for some reason - is determined to oppose electronic cigarettes, regardless of the actual scientific evidence. He is grasping at straws, trying to find any shred of evidence - whether valid or not - to support his contention, apparently a pre-determined one, that electronic cigarettes are making it more difficult for smokers to quit.
There are literally tens of thousands of former smokers out there who will find this a joke, as they successfully quit thanks to electronic cigarettes. Moreover, an actual clinical trial which did measure quitting among smokers in a longitudinal fashion and did randomize smokers to NRT vs. e-cigarettes, found that electronic cigarettes are every bit as effective as the nicotine patch for smoking cessation. In the light of that evidence, how can Dr. Glantz continue to argue that electronic cigarettes inhibit smoking cessation?
My opinion is that much like the rest of the anti-smoking movement, Dr. Glantz is so blinded by ideology that he cannot bring himself to condone a behavior that looks like smoking, regardless of what the evidence shows or the experience of vapers tells us.
Ideology is not necessarily a bad thing. In fact, the strong ideology in the anti-smoking movement is probably what helped it to become such a strong and successful movement. But at some point, you need to be able to critically evaluate scientific evidence without the cloud of ideology. One can still be a passionate advocate without losing scientific integrity. Sadly, we have reached the point where the anti-smoking movement has lost its ability to do that. The ideology has become so dominant that it is drowning out the rigorous scientific analysis that I believe used to guide the movement.