One of the flawed studies, titled, “Electronic Cigarette Use and Myocardial Infarction Among Adults in the US Population Assessment of Tobacco and Health,” was published in the Journal of the American Heart Association in 2019 and co-authored by the infamous Stanton Glantz. The cross-sectional study used data from the baseline survey of the 2013-2014 Population Assessment of Tobacco and Health (PATH) study, looking for a relationship between vaping and heart attacks.
The study authors found that people who vaped were more likely to report ever having had a heart attack in the past, and had subsequently concluded that e-cig use doubles one’s chances of having a heart attack.
It is actually the heart attacks “causing” the vaping
Responding to the claims on his blog page, “The Rest of the Story”, at the time, Siegel had pointed out “that the problem with drawing a causal conclusion from this cross-sectional study, is that there is no way to know which came first: the vaping or the heart attack.” As highlighted in response to similar studies, Siegel pointed out that it is fairly common for former smokers to switch to vaping after experiencing heart attacks and other health scares.
“If this is the case, then it is not the vaping that is causing the heart attacks; instead, it is really the heart attacks “causing” the vaping. In epidemiology, we call this “reverse causation,” and it is a common limitation of cross-sectional studies, especially when they do not ask about the time course of exposures and outcomes,” he explained.
Sure enough, after multiple submissions by fellow academics, the journal pointed out that the study had failed to specify what came first, the vaping or the heart attacks. When asked to provide further data to determine the direction of this relationship, Glantz and his team failed to do so, leading to the retraction of the study.
Only vapers who also smoked were at a increased risk of heart attacks
Meanwhile, the new study by Siegel and his team, collected data from 175,546 respondents to the annual National Health Interview Survey from 2014 to 2019. They found that daily e-cigarette use was only associated with higher heart attack incidence among people who were also currently smoking regular cigarettes.
Moreover, they found no evidence of increased heart attacks risk among vapers who had never smoked. These findings confirm Siegel’s earlier suspicions, that the initial study had drawn its conclusions about a perceived relationship between vaping and smoking without factoring in smoking, which in this case is no doubt a very significant variable.
