Study Claims E-Cigarettes Make It Harder to Quit Smoking, Gets Labeled as Junk Science
A study carried out by researchers from the University of California and San Diego State University found that people who had ever used e-cigarettes were half as likely to quit smoking or even reduce their cigarette consumption compared to people who said they would never use electronic cigarettes.
Considering the controversy regarding whether e-cigarettes actually help smokers quit, this scientific work might be considered a heavy blow for vaping, which it was, but only because the media simply decided to present its findings as conclusive evidence, without considering its serious limitations.
The study of Prof. Wael Al-Delaimy et. al. involved a survey of 1,000 smokers in California who were followed for a year to determine whether they had managed to quit smoking. After comparing the quit rates of people who said they had ever used e-cigarettes at both baseline and 12-month followup to those who stated they would never use them, the researchers found that the former were less than half as likely to have quit smoking. This led them to the conclusion that electronic cigarettes inhibit smoking cessation.
E-cigarette opponents no doubt had a field day when this study was published in the American Journal of Public Health, but luckily, there are still people out there who care about proper science and can spot a legit study from a superficial one. One such person is Dr. Michael Siegel, a Professor in the Department of Community Health Sciences at Boston University School of Public Health. On his blog, Dr. Siegel analyzed the work of Prof. Wael Al-Delaimy et. al., pointing out its many limitations and explaining why its conclusion is invalid.
First of all, although the study abstract claims it surveyed 1,000 smokers, the results are presented only for 368 smokers. The other 632 were either thrown out of the study or removed from the analysis, for a variety of reasons: anyone who had not heard of e-cigarette was eliminated, those who had not used e-cig but reported that they might use them in the future were excluded from the primary analysis, anyone who at baseline said they would never used electronic cigarettes, but at followup that they had or might use them, was eliminated and, lastly, those who at baseline said they had used e-cigarettes but at followup that they had not, was removed.
The very selection process of the cohort, excluding several categories of smokers, some by using followup variables “has introduced a strong bias towards finding a much higher quit rate among the control group”, as Dr. Siegel notes.
Furthermore, while the study claims that it compared smokers “who ever used e-cigarettes” with those “who never used e-cigarettes.”, in reality it actually compared smokers who said they had ever used e-cigarettes at baseline with those who reported, both at baseline and follow-up, that they would never use e-cigarettes. The very fact that someone would say that they would never use electronic cigarettes further introduces a huge bias into the study.
But, perhaps the most important aspect of this study was that anyone who had ever used an electronic cigarette was included in the “intervention” group, even if they might have tried the device once, years ago, with no intention of quitting smoking. Even if one such person might have tried a form of nicotine replacement therapy (nicotine gum, patches, etc.) to quit smoking at baseline and failed, their failure would be counted against the e-cigarette users group.
“This study has so many flaws that I find its conclusions to be meaningless. It is an example of junk science at (almost) its worst,” Dr. Michael Siegel writes. “But what makes it even more problematic is the apparent deception with which the results and conclusions of the study were presented. They left out important details that are critical to understand what the study did and did not do. Anyone but the most thorough and critical reader would easily be deceived by these omissions.”
And he is certainly not the only one to have noticed the superficial nature of Al-Delaimy et. al. study. Ricardo Polosa, Professor of Internal Medicine at the University of Catania and scientific director of the Italian Anti-Smoking League, also declared himself disappointed by the research. “Professor Al-Delaimy and I have published several cohort studies in the field of asthma and smoking together, and I have great respect for his level of professional preparation,” Prof. Polosa said. “I was therefore very surprised to see significant methodological lightness in his new study. The questions are asked in order to introduce an important methodological bias by establishing the a priori exclusion of those who would benefit from the use of e-cigarettes in time . This limits the ability to count successes in quitting smoking for potential users of electronic cigarettes.”
“This study – said the reputed Italian scientist – is likely to do great damage to public health, fueling the anti-e-cigarette propaganda by discrediting the solid evidence in support of electronic cigarettes as a way of quitting smoking”.
The UK National Health Service (NHS) website also published an article on this subject titled “Study Doesn’t Prove E-Cigs Make Quitting Smoking Harder“. It states that because this was a longitudinal study it cannot answer if whether electronic cigarettes help or inhibit smoking cessation. “It can only look at associations between reported e-cigarette use at one point in time and quitting later. It cannot tell us whether e-cigarette use is directly causing the quitting (or lack of quitting) or what other factors may be involved. High-quality randomised controlled trials would be needed for that.”
“This might look like a significant finding considering the controversy over whether e-cigarettes are a useful aid to quitting. But we don’t know whether the people who used e-cigarettes were actually using them to try and quit, or whether they actually used them between the first and second surveys. There may be many factors including lifestyle and use of other smoking cessation therapies, which were not considered by the researchers,” The NHS article notes.
Unfortunately, as it’s always the case with negative stories of studies on electronic cigarettes, the harm has already been done. The internet is full of scary articles relating to this study, and as Dr. Siegel points out, the vast majority don’t mention the limitations that make its conclusion invalid.
