The study, which looked at the habits of 88 smokers
who also used e-cigarettes, was published as a research letter in
the journal JAMA Internal Medicine on Monday. It found that smokers
who also used e-cigarettes were no more likely to quit smoking after
a year, compared to smokers who didn't use the devices.
Outside experts say the small number of respondents, and a lack of
data on whether they intentionally used e-cigarettes to help them
quit smoking, mean the findings from the Center for Tobacco Control
Research and Education at the University of California, San
Francisco can't take the place of much more rigorous study on the
E-cigarettes were first introduced in China in 2004 and have since
grown into a $2 billion industry. The battery-powered devices let
users inhale nicotine-infused vapors, which don't contain the
harmful tar and carbon monoxide in tobacco.
At issue is how strictly U.S. health regulators should control the
products. Advocates say e-cigarettes can help smokers quit. Public
health experts fear they can serve as a gateway to smoking for the
uninitiated, particularly teenagers. Leading U.S. brands include blu
by Lorillard Inc and products from privately-held NJOY and Logic
A previous report from the UK found that people who use e-cigarettes
primarily want to replace traditional cigarettes (see Reuters Health
story here: http://reut.rs/1ceF7nT).
"We did not find a relationship between using an e-cigarette and
reducing cigarette consumption," Rachel Grana, the lead researcher
on the new study, told Reuters Health.
Grana and colleagues at the University of California, San Francisco
analyzed 2011 survey data collected from 949 smokers. Of those, 88
reported using e-cigarettes.
When the researchers looked at those smokers' responses a year
later, they found that the people who reported using e-cigarettes in
the 2011 survey were no more likely to quit smoking than the people
who didn't use e-cigarettes.
For those who were still smoking in 2012, using e-cigarettes also
didn't appear to change how many traditional cigarettes people
smoked per day.
The researchers note that the small number of participants who
reported using e-cigarettes may have limited their ability to detect
a link between quitting smoking and using the device.
Dr. Michael Siegel, who was not involved with the new research, told
Reuters Health that the new study had several design flaws,
including that the researchers did not know why some of the
participants tried e-cigarettes or how long they had used them.
Siegel is an expert on community health at Boston University School
of Public Health and has studied e-cigarette research.
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By comparing people who smoked regular cigarettes
and those who smoked e-cigarettes, the researchers are assuming
"that the groups are exactly equivalent in terms of their
motivations and their levels of addiction to cigarettes," Siegel
said. "You can't make those assumptions. You're not dealing with
In an emailed statement, Grana and fellow researchers acknowledged
that they did not have information on the participants' motivations
to use e-cigarettes, but said their analysis took into account other
factors known to be linked to quitting smoking, such as their stated
intention to quit and how many cigarettes they already smoked each
"These factors may also reflect motivations to
use e-cigarettes, as e-cigarettes are frequently marketed and
perceived as cessation aids," they wrote. "While these factors
predicted quitting as expected, we found that e-cigarette use did
not predict quitting.
Siegel also pointed out that only about eight percent of the people
surveyed said they had any intention to quit smoking within the next
month. He hopes people will reserve judgment on e-cigarettes until
randomized controlled studies — considered the "gold standard" of
medical research — are published.
"We need solid data that's based on solid science before we make
decisions," he said. "I hope no one would take this research letter
and make any conclusion based on it."
JAMA Internal Medicine, online March 24, 2014.
(Editing by Nancy Lapid and Michele Gershberg and Andrew Hay)
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