‘Hold your horses’

A US public health expert has shone a new light on the results of a widely reported study claiming that vaping causes heart attacks.
On his tobacco analysis blog, Dr. Michael Siegel, a professor in the Department of Community Health Sciences, Boston University School of Public Health, said the new study, which had been presented on Saturday at the annual meeting of the Society for Research on Nicotine and Tobacco (SRNT), had concluded that vaping caused heart attacks, increasing the heart attack risk for dual users beyond that of smoking alone.
The research has not yet been published but was presented as a poster at the conference.
‘The study was a cross-sectional analysis of nearly 70,000 respondents to the combined 2014 and 2016 National Health Interview Surveys (NHIS), a nationally representative survey of health risk factors and outcomes in US adults,’ Siegel’s blog explains. ‘Respondents were asked to report their current vaping and smoking statuses and to report whether they had ever had a heart attack. The researchers found that there was a significant association (odds ratio = 1.8) between daily e-cigarette use and having experienced a heart attack. The analysis controlled for level of current cigarette use.
‘Based on this observation, the study concludes that daily e-cigarette use doubles the risk of heart attacks.’
At this point, Siegel reports ‘The Rest of the Story’.
‘Hold your horses,’ he warns.
‘Before accepting the conclusion that vaping causes heart attacks in unsuspecting smokers, remember the old adage: correlation does not equal causation. This study is a perfect demonstration of that phenomenon.
‘Because this is a cross-sectional study, and because respondents were asked whether they had ever had a heart attack, one cannot determine whether the heart attacks followed e-cigarette use or preceded it. In other words, we do not know that vaping preceded the heart attack for any of the subjects. It is entirely possible that in most of these cases, the smokers suffered a heart attack and then started vaping in an attempt to quit smoking. In fact, I believe that is the most likely explanation for the observed study findings.’
The rest of The Rest of the Story is at: http://tobaccoanalysis.blogspot.co.uk/2018/02/new-study-concludes-that-vaping-causes.html.