The study titled, “Association of E-Cigarette Use With Respiratory Disease Among Adults: A Longitudinal Analysis,” reported that adults who used e-cigarettes at baseline and had never been diagnosed with lung disease, were more likely than non-vapers at baseline, to be told that they have lung disease after three years of follow-up.
Based on these findings, the authors concluded that vaping must be considered as an independent risk factor for lung disease. “Use of e-cigarettes is an independent risk factor for respiratory disease in addition to combustible tobacco smoking. Dual use, the most common use pattern, is riskier than using either product alone.”
However, while the researchers did control for whether a person reported smoking or not at baseline, they failed to control for the participants’ lifetime smoking history. Therefore, any existing lung damage caused by previous smoking, was not accounted for in any way.
“The study is deeply flawed”
Commenting about the study, renowned anti-smoking and public health expert Dr. Michael Siegel naturally pointed out that it “is deeply flawed.” He explained that it fails to consider something really obvious, the main reason why most people start vaping, is to quit cigarettes. Therefore vapers who don’t currently smoke are most likely ex-smokers.
“…It fails to consider the most likely explanation for the study findings: that people who use e-cigarettes more likely have a history of more intense smoking than people who do not use e-cigarettes. For example, one study found that while only 21% of adult smokers who did not vape were heavy smokers, 68% of adult smokers who did vape were heavy smokers (or had been heavy smokers),” said Siegel.
“This is critical because it shows that in order to control for smoking history properly in a study such as this one, you cannot merely control for whether or not someone was a current or ever smoker at baseline. You have to actually control for the person’s overall smoking history including whether they were a heavy smoker and how many years they smoked,” he added.
Smoking history is an obvious predictor of one’s lung health
The expert pointed out that of course smoking history is a strong predictor of one’s lung health, so not controlling for it invalidates the study. “Because smoking history is such a strong predictor of the development of chronic lung disease, the failure to control for smoking history invalidates the results of this study. In my view, it does not provide any evidence that e-cigarette use causes lung disease. What it does show, in contrast, is that smoking is a strong predictor of lung disease and that heavier intensity of smoking increases the risk.”
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