According to foreign reports, a new study shows that smoking is not associated with an increase in incidence rate of heart disease among people without smoking history. Previous studies have claimed that this association is flawed in methodology.
The paper, published in the American Journal of preventive medicine, refutes three earlier studies that widely linked e-cigarettes to a higher risk of heart attack, even among people who had never smoked.
"Among people who never smoked, the use of e-cigarettes was not associated with an increased risk of heart attack." Dr. Michael Siegel, a professor of Community Health Sciences at Boston University and one of the authors of the new study.
A study published in the American Journal of preventive medicine in 2018 claimed that smoking e-cigarettes every day would increase the risk of heart attack. However, it only included participants who used both e-cigarettes and combustible cigarettes - participants who did not use e-cigarettes alone.
Another group of researchers skeptical of this method issued a reply, saying it was important to check the so-called connection between people who had never smoked combustible cigarettes. The author of the initial study published a reply to the reply, saying that such a distinction was unnecessary.
At the same time, two other papers were published according to the original paper, which provided further harmful legitimacy for the link between e-cigarettes and heart disease.
The second of the two papers, one of its co authors, Dr. Stanton Glantz, a famous opponent of reducing tobacco harm, was once a mentor of Siegel. The article was withdrawn in 2020 because its claim that e-cigarettes can cause heart attacks is based on evidence including heart attacks before heart attacks.
Obviously, the previous conclusion that the use of e-cigarettes itself can lead to heart attack is wrong.
This new study, written by Siegel and Dr. Clayton critcher, a business professor at the University of California, Berkeley, analyzed the data of 175546 respondents in the annual National Health Interview Survey from 2014 to 2019.
They found that the incidence rate of heart attacks was higher in people who used electronic cigarettes only daily than those who currently smoke combustible cigarettes. There was no evidence that the smokers who had never smoked combustible cigarettes increased the risk of heart disease.
That is, the initial study reached conclusions about perceived causes (e-cigarette) and effects (heart attack) without considering key variables (smoking).
It seems inexplicable that the original 2018 paper omitted the data of 2015, and so did the subsequent papers based on it. " It seems strange that they ignore the data of that year when the data are easy to obtain. " Siegel said.
A reanalysis of the data set used in the original study, together with the recently available data and the missing 2015 data, shows that the association between e-cigarette use and heart attack depends on a person's smoking history.
Correlation is not causality. When researchers fall into such a trap, correlation is worrying.
Kretcher and Siegel acknowledge that a more thorough analysis of previous studies will find that e-cigarettes are relatively new, limiting our ability to assess long-term health effects and compare them with combustible tobacco smoking. But it is clear that the conclusion of previous studies - the use of e-cigarettes itself can lead to heart attacks - is wrong.
Bad research has led to bad policies in the field of tobacco harm reduction, making it more difficult for smokers to turn to safer choices. Correlation is not causality. When high-quality researchers fall into such a trap, it will be worrying - at the expense of accurate public health information. The correlation between e-cigarette use and the incidence of heart attack cannot be used as evidence that e-cigarette use increases the incidence of heart attack.
"By analogy, if a person models height as a function of weight, then the output cannot be used to simulate the counterfactual scenario to understand how short a person will be after losing weight." Kretcher and Siegel wrote.