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 Use | Bhatta-Glantz Original Results | Results After Correct Classification |
|
|
|
| Never | Referent | Referent |
| Non-Daily Current | 1.99 (1.11 – 3.58) | 0.18 (0.05 – 0.66) |
| Daily Current | 2.25 (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.