Wednesday, August 26, 2020

Re-Analysis of Retracted Research on Heart Attacks Before Vaping

Dharma Bhatta and Stanton Glantz last year published a study claiming that e-cigarettes cause heart attacks. That assertion was based on 38 heart attack incidents, but the authors knowingly included people who had heart attacks years before first using e-cigarettes.

My economist colleague Nantaporn Plurphanswat and I described that fatal error in two letters to editors of the Journal of the American Heart Association.  I applied pressure for the next seven months, and the editors retracted the study on February 18 of this year.

Although the incident was reported by USA Today’s Jayne O’Donnell, Ivan Oransky at Retraction Watch, Alex Norcia of Vice and others, the tobacco research community showed little interest. Despite the obvious research flaw, some insisted that we show the effect of correctly classifying vapers who had heart attacks years before starting e-cigarette use.

Dr. Plurphanswat and I have met that challenge, and we now report our results in the professional journal Addiction.

From the public-use dataset we know that at least 11 of Bhatta-Glantz’s reported 38 heart attacks occurred prior to e-cigarette use.  But there are many more.  For our re-analysis we determined the exact number of prior heart attacks, but we cannot disclose that figure due to restrictions imposed by the Inter-university Consortium for Political and Social Research. Following are our results after correctly classifying all of the prior heart attacks.


Adjusted Odds Ratios For Heart Attack According to E-Cigarette Use
E-Cigarette UseBhatta-Glantz Original ResultsResults After Correct Classification

Non-Daily Current1.99 (1.11 – 3.58)0.18 (0.05 – 0.66)
Daily Current2.25 (1.23 – 4.11)0.69 (0.22 – 2.12)


Our work reveals that Bhatta and Glantz’s doubled odds ratios disappear after correctly classifying the time-warped e-cigarette heart attacks. 

Our article describes additional problems with the Bhatta-Glantz study, such as the fact that their definitions were internally inconsistent. They excluded current experimental e-cigarette users and smokers, but they included former experimental e-cigarette users and smokers, with no justification. Additionally, participants were not counted correctly. Bhatta-Glantz used all 32,320 survey participants in their analyses, but 7,183 of those had missing information on key variables; we don’t know what Bhatta and Glantz did with them, but they should not have been counted.

We note, “[Bhatta and Glantz] appeared to know about detailed information regarding when participants were first told about the heart attack and when they first used e-cigarettes. On page 9 of their [retracted] article, the authors said that they used those specific PATH survey questions to ‘address this problem’ of temporality with a secondary analysis ‘to select only those people who had their first MIs [myocardial infarctions] at or after 2007’ (n = 16, their Supporting Information, Table S6). Glantz also told a journalist that the secondary analysis reflected the timing of the heart attacks. However, despite this knowledge and claim, their secondary analysis did not address the temporality problem. We found that more than one-third of the current 16 e-cigarette users who had a heart attack after 2007 occurred before they first used e-cigarettes.” 

We conclude, “…[Bhatta and Glantz] did not account for heart attacks that occurred before first e-cigarette use, even after the temporality problem was raised in pre-publication peer review…The analysis presented here supports the decision by editors of the Journal of the American Heart Association to retract Bhatta & Glantz’s article on 18 February 2020. It raises questions as to what analyses the authors may have undertaken that were not reported and why they did not conduct the analyses reported here or requested during peer review of the original article.”

As I noted previously, the retracted study was supported by $13.6 million from American taxpayers.  Our new research warrants an investigation by federal officials to determine if those funds were misused. 



Wednesday, August 19, 2020

California Researchers Make Dramatic Claims About E-Cigarettes & Covid-19, But Fail to Disclose Minuscule Case Numbers

The Journal of Adolescent Health published a study on August 11, by faculty from Stanford and the University of California, San Francisco, with senior author Bonnie Halpern-Felsher. Four thousand adolescents and young adults age 13-24 years were asked about ever using cigarettes or e-cigarettes, and having Covid-19 symptoms, tests and diagnoses.

The researchers’ bold claims can be seen in the Stanford Medicine webpage pictured above. Young people ever using e-cigarettes were five to seven times more likely to be diagnosed with Covid-19. Stanford Medicine promoted the study in a press release, and it was cited by Congressman Raja Krishnamoorthi as a reason for the FDA to ban e-cigarettes as a Covid-19 hazard: “we have the evidence that the FDA was waiting for, and it can no longer deny the danger e-cigarettes pose during the coronavirus crisis.”

I have analyzed the study. While the authors failed to provide raw numbers of the ever e-cigarette users who were diagnosed with Covid-19, one can use their odds ratios to estimate those numbers. I have added them, in red, to the Stanford Medicine webpage below.



Because my estimates are approximate (they might be one lower or higher), I asked the senior author to provide actual numbers. She declined.

Researchers making extreme claims intended to influence national health policy are obligated to provide hard data. These California researchers have failed to do so.




Tuesday, August 11, 2020

Compelling Evidence that Smoking Protects Against Covid-19 & Reduces the Likelihood of ICU Admission

Long-term cigarette smoking is associated with a number of serious diseases, but not COVID-19. In fact, numerous studies demonstrate that smokers are far less likely to be diagnosed with coronavirus than are non-smokers. In June, Konstantinos Farsalinos and colleagues reviewed 18 published reports, finding “an unexpectedly low prevalence of current smoking among hospitalized patients with COVID-19.” (here). 

It is, however, an understatement to say that the quality of COVID-19 information and data is poor. That partly explains why the protective effect of smoking has not generated significant mainstream interest. That is likely to change. 

Last week, researchers from the Universities of Oxford and Nottingham published a prospective cohort study of 19,500 coronavirus patients in the UK, 1,300 of whom ended up in intensive care units (ICUs) (here).  Their analysis, published in the British Medical Journal, found that smokers are far less likely to be diagnosed with COVID-19 and less likely to be admitted to an ICU.


The magnitude of the protection is not marginal. The above chart from the article shows that smokers are less than half as likely as non-smokers to be diagnosed with COVID-19.  Even more impressive, light smokers are 74% less likely to be in an ICU, and heavy smokers are 93% less likely. 

The BMJ study confirmed the elevated risks for other factors. For example, people over 60 years old were about twice as likely to be diagnosed and 6-7 times more likely to be in an ICU.  People with Type I diabetes were nearly three times more likely to be both diagnosed and end up in an ICU.  A body mass index of 30+ increased diagnoses by 24-60% and ICU admissions by 3- to 4-fold.  

Although smokers are clearly protected from COVID-19, it is not known how this is achieved. Farsalinos and colleagues believe that nicotine plays a role (here), however, fully understanding the mechanism will require a lot more research.

This is not an invitation to start smoking, but if the mechanism of protection involves nicotine, this finding might lead to a better understanding of how to avoid and treat this devastating pandemic.