If I said the words "heavily biased report," "cherrypicks studies that agree with its position and ignores studies that don't," "uses studies in ways that the study authors say are inappropriate," most tobacco control advocates would assume I am talking about a historical Big Tobacco report. Little would they suspect that what I am actually referring to is a report by the California Department of Public Health.
Sadly, I am referring to precisely that. A newly-released report on electronic cigarettes from the California Department of Public Health purports to provide a scientific review of the topic. Today, I examine the information it presents about the efficacy of e-cigs for smoking cessation and the evidence upon which it bases its conclusion.
The report concludes that: "There is no scientific evidence that e-cigarettes help smokers successfully quit traditional cigarettes or that they reduce their consumption."
This conclusion is based on only one peer-reviewed, observational study, which "found that e-cigarette users are a third less likely to quit cigarettes, suggesting that e-cigarettes inhibit people from successfully kicking their nicotine addiction."
The Rest of the Story
The study upon which the report most heavily relies is the Vickerman study. This is the study which the report claims found that e-cigarette users are a third less likely to quit cigarettes. As I have explained
in detail elsewhere, the data from the Vickerman study cannot be used to
assess the effectiveness of e-cigarettes for smoking cessation. 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.
Even the author of the study stated most clearly that it was not designed to examine the efficacy of e-cigarettes for smoking cessation, and that it could not and should not be used for that purpose: "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."
Moreover, 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."
While the California DPH report relies upon a survey, an unpublished presentation, and the Vickerman paper, none of which were designed to determine the efficacy of electronic cigarettes for smoking cessation, there have been three clinical trials which were designed specifically to answer this question. Two were conducted by Dr. Riccardo Polosa and colleagues in Italy. One was conducted by Dr. Bullen and colleagues in New Zealand. These three studies are the best and most rigorous scientific information we have on the efficacy of electronic cigarettes.
So here's a question:
In the California DPH's comprehensive report, how many of these 3 clinical trials did it consider in determining its conclusion regarding the effectiveness of electronic cigarettes for smoking cessation?
The answer is ....
....None of the above.
The report doesn't consider a single one of these clinical trials, none of which is cited in the report.
In conclusion, this report is severely biased. It draws conclusions about the efficacy of e-cigarettes from studies that were never designed to measure the efficacy of e-cigarettes. It cherrypicks the studies that support its pre-determined conclusion and excludes studies that don't support this conclusion. It doesn't cite a single one of the three clinical trials which provide the most rigorous evidence regarding the effectiveness of e-cigarettes for smoking cessation.
This is exactly the type of thing we used to see from the tobacco industry in the past. But the rest of the story is that a health agency is now using precisely the same shoddy science techniques. There is apparently so much hysterical zeal against electronic cigarettes that science has lost its rightful place in the tobacco control movement.
The CDHS report goes even further than most e-cigarette opponents by arguing that there isn't even any evidence that electronic cigarettes can help smokers reduce their consumption. But that is an outright lie. There is tremendous evidence that e-cigarettes help smokers reduce their consumption. In fact, even among smokers who had no interest in quitting, more than 50% were able to cut their consumption by at least one-half after trying e-cigarettes. Numerous other studies have documented the same phenomenon. Even the most vigorous e-cigarette opponents have acknowledged that e-cigarettes are often associated with a significant reduction in cigarette consumption.
I actually agree with many of the measures recommended by the CDPH report, such as requiring leakproof containers for e-liquids, requiring childproof packaging, and conducting public education campaigns to reveal the truth about these products (and especially, about the relative risks between smoking and vaping). However, I do not condone the use of shoddy science, reminiscent of the tobacco industry of old, in order to support the need for these actions. The truth is enough. And in public health, we should offer the public nothing but the truth.