Saturday, February 09, 2019

Researchers Tell Public that Vaping Causes COPD as Scientific Rigor in Tobacco Control Drops to an All-Time Low

Based on the results of a cross-sectional study showing an association between using e-cigarettes and reporting that one has ever been told they have COPD (chronic obstructive lung disease), a number of researchers have essentially concluded that vaping causes COPD, and one researcher is telling the public that use of e-cigarettes increases one's risk of COPD just like cigarettes.

The paper, published in Drug and Alcohol Dependence, reports the results of a cross-sectional study based on the 2016 Behavioral Risk Factor Surveillance System (BRFSS) survey in Hawaii. The outcome variable was reporting ever having been told that one has COPD. The main predictor variable was ever having used an e-cigarette. The key finding of the study was that: "there was a significant association of e-cigarette use with COPD among nonsmokers (AOR = 2.98, CI 1.51–5.88, p <  .01), but the association was not significant among smokers (AOR = 1.29, CI 0.94–1.77, ns.)."

The paper concludes that: "The fact that findings for respiratory symptoms occurred primarily for nonsmokers argues against several alternative interpretations of the results." In other words, the paper is essentially arguing that this is most likely a causal effect (i.e., vaping causes COPD).

The Rest of the Story

There is absolutely no way one can conclude, or even speculate, based on the results of this cross-sectional study, that vaping is a cause of chronic obstructive lung disease. Remember, we are talking here about emphysema and chronic bronchitis (that's what is meant by COPD).

To see how ridiculous such a conclusion, or even such speculation is, one needs only to look at the sample size of never smokers in the 2016 Hawaii BRFSS who were current e-cigarette users and reported having COPD. It's 13 (based on the CDC's BRFSS online analysis tool). According to the article itself, the total sample of never smokers who were current vapers was only 45. A simple bivariate online analysis of the relationship between ever use of e-cigarettes and ever diagnosis of COPD among the never smokers in the 2016 Hawaii BRFSS reveals no significant association.

If you do the same analysis using the entire 2016 BRFSS (including all states), the proportion of never smokers who report having been diagnosed with COPD is actually higher among non-vapers (2.9%) than ever vapers (2.4%).

It's not just that there are dangers with drawing causal conclusions like this from a cross-sectional study. In this case, the sample size upon which the conclusion is being drawn is so low that the analysis is not at all reliable to begin with.

The paper ignores (and does not cite a single article from) a body of literature showing that smokers with COPD who switch to electronic cigarettes experience an improvement in their symptoms.

However, the worst problem with these conclusions (and even with the speculation) is that it is biologically implausible that vaping for a few years can cause emphysema or chronic bronchitis. Since vaping did not become widely popular until about 2011, the average number of years that the vapers in the 2016 Hawaii BRFSS used e-cigarettes could not be more than about five years.

There is simply no way that you can develop COPD from vaping for five years. Even among heavy chain smokers, it takes several decades before they develop COPD. I'm not aware of more than a handful of smokers who were diagnosed with COPD (caused by smoking) before they reached the age of 40. Population-level data show that the observed increase in COPD incidence among smokers does not begin until about age 45.

Even assuming that someone did not start smoking until they reached 20, it still takes a minimum of two decades of smoking to do enough damage to the lungs that a person develops and is diagnosed with COPD. So how can you get COPD from vaping (which is even less frequent than smoking) for just a few years?

People are just not thinking. The idea that there are a substantial number of never smokers in Hawaii who have developed COPD after just a few years of vaping is absurd on its face.

This leads me to believe that there is a strong, subconscious bias among many researchers who are so determined to find an association between vaping and chronic disease that they are forgetting basic pathology.

Moreover, there have not even been anecdotal reports of nonsmokers developing COPD after a few years of vaping. And clinical studies have failed to detect any decline in lung function, as measured by spirometry, among vapers.

Furthermore, if vaping was causing COPD, we would expect to see an increase in the prevalence of COPD over the past few years, especially since vaping rates started to increase exponentially starting in about 2011. Instead, we see little if any change in COPD prevalence since 2011.

The reason this is all so disturbing to me is not simply that it shows how scientific rigor in tobacco control literature has deteriorated. It is disturbing because disseminating these scientifically unsupported claims is going to discourage many smokers from trying to quit using e-cigarettes and may even cause many former smokers to return to smoking. After all, if you can get COPD from vaping, then why not go back to the real thing?

The unsupported, sweeping, hysterical conclusions being drawn from these studies are not just scientifically poor, they are causing harm to the public's health as well.

1 comment:

Michael J. McFadden said...

"it shows how scientific rigor in tobacco control literature has deteriorated."

Michael, I think it's BEEN deteriorated since at least the 1990s, most definitely since the Helena era, and likely even going back into the 1970s when I first became aware of the lies coming from ASH et al.

Has it deteriorated more? I don't know. There comes a point where it simply doesn't matter how deep the cesspool is: you're going to drown a miserable death regardless...

-MJM, a swimmer against the tide...