Substantial evidence of e-cigarette use among never and former smokers (both adults and youth): That's not harm reduction

E-cigarette enthusiasts, as well as much of the research on e-cigarettes, assumes that use will be concentrated among current smokers who are either using e-cigarettes to quit or reduce smoking.  For example, the American Heart Association in its recent policy statement on e-cigarettes says, “Among never smokers, 0.7% were currently users (past 30 days), which indicates that few never smokers
who try e-cigarettes continue their use.”
 
Lauren Dutra and I recently reviewed the evidence that a substantial and growing minority of youth using e-cigarettes have never smoked conventional cigarettes.
 
There are several recent papers that show substantial e-cigarette use among never-smoking adults or adults who have long-since quit smoking.
 
Robert McMillen and colleagues used data from national surveys conducted between 2010 and 2013 to examine adult use of e-cigarettes.  Consistent with earlier research, they found dramatic increases in e-cigarette use, from 1.8% in 2010 to 13.0% in 2013.  Use among young adults (age 18-24) was highest, probably reflecting the heavy marketing directed at this group (which spills down to teens).  While two-thirds of adults were current smokers, 32.5% of current e-cigarette users were never or former smokers.
 
That 32.5% includes 12.6% who are never smokers and 5.8% who quit smoking more than 5 years ago, before e-cigarettes entered the market.  The other 14.1% are people who quit smoking less than 5 years ago so it is possible that some of them used e-cigarettes to quit smoking.  What that means is that at least 18.4% –  nearly 1 in 5 – e-cigarette users are people who would not be using nicotine and being exposed to the other toxins in e-cigarettes if e-cigarettes were not on the market.
 
The actual use of e-cigarettes among nonsmokers is likely higher than these numbers because McMillen and colleagues pooled the results for the four years in the analysis of nonsmokers’ use of e-cigarettes and use has been increasing over time.
 
Blair Coleman and colleagues help explain these findings, at least among young adults.  They examined the relationship between openness to smoking conventional cigarettes among never-smoking (i.e., people who had not smoked 100 cigarettes in their lifetime and had not smoked in the last 30 days) young adults (age 18-29) in the 2012-2013 National Adult Tobacco Survey and found that young adults who used e-cigarettes were 2.4 times the odds of being open to cigarette smoking.  (They found similar, but smaller, effects for hookah and cigars, but not smokeless tobacco.)  The effect was 1.7 times higher among younger young adults (age 18-14), meaning that in this younger group e-cigarette users were 4.1 times (2.4 x 1.7) more likely to be open to smoking cigarettes than nonusers
 
These results are consistent with the results in middle and high school students that Rebecca Bunnell and colleagues found in the 2011-2013 National Youth Tobacco Survey.  They found that between 2011 and 2013 the number of never-smoking youth who used e-cigarettes increased 3-fold, from 79,000 to over 263,000.  In addition, youth who were ever and current e-cigarette users had 1.7 and 1.9 times the odds of having smoking intentions than never e-cigarette users.
 
These results are also consistent with our finding (based on the 2011 National Youth Tobacco Survey) that among cigarette experimenters (>1 puff), ever e-cigarette use was associated with higher odds of ever smoking cigarettes (>100 cigarettes) by a factor of 6.3 and current cigarette smoking of 6.0.
 
As with the McMillen study, these effects are probably underestimated because much of the data were collected before the explosion of e-cigarette advertising that occurred in recent years.
 
These effects are substantial.  It is time for e-cigarette enthusiasts (and policy makers) to seriously consider the effects of e-cigarettes on never or former tobacco users, whether adults or youth.  Recruiting new people to (or back to) nicotine addiction is a bad thing.  For these people the appropriate toxicity comparison is not with cigarettes but with not smoking anything at all.

Comments

Are you saying you'd rather

Are you saying you'd rather that young people start smoking tobacco cigarettes instead of vaping "e-cigarettes"? While using neither may be the ideal, given the choice between the two I'd much rather see someone use an "e-cigarrette" than tobacco, since there is no combustion with vaping, and it's the combustion of the tobacco, not the nicotine, which causes all of the health risks associated with smoking.

No

This study, as well as earlier studies of kids, show that there are a substantial number of kids who have never smoked a cigarette are inititaing nicotine addiction with e-cigarettes.
 
There is no evidence to date showing that these kids are using e-cigarettes instead of cigarettes.

Use of electronic cigarettes in Great Britain (2014 Survey)

 
Action on Smoking and Health (ASH-UK) released their latest survey -  http://www.ash.org.uk/files/documents/ASH_891.pdf
 
They also updated their Electronic Cigarettes Brief - http://www.ash.org.uk/files/documents/ASH_715.pdf
 
 
• ASH estimates that there are currently 2.1 million adults in Great Britain using electronic
cigarettes, Of these, approximately 700,000 are ex-smokers while 1.3 million continue to
use tobacco alongside their electronic cigarette use. Electronic cigarette use amongst never
smokers remains negligible.
 
Total sample size was 12,269. Fieldwork was undertaken between 5th and
14th March 2014. All surveys were carried out online. The figures have been weighted and are
representative of all GB Adults (aged 18+).
 
• Among children, sustained use is rare and generally confined to children who
currently or have previously smoked. Eight percent (13% among 16-18 year olds) had
tried electronic cigarettes at least once or twice. Two percent reported using them monthly
or weekly. Among children who reported ever using electronic cigarettes, 33% had used
them in the last month. Of those who had heard of e-cigarettes and had never smoked a
cigarette, 98% reported never having tried electronic cigarettes and 2% reported having
tried them “once or twice”. There is almost no evidence of regular electronic cigarette use
among children who have never smoked or who have only tried smoking once.
 
• Few children who have never used them expect to use an electronic cigarette soon,
except those who already smoke. Only 1% of those who had never smoked think that
they would try an electronic cigarette soon. This remained unchanged from 2013.
 
• Frequent (more than weekly) use of electronic cigarettes by children was confined
almost entirely to ex-smokers and daily smokers.

Total sample size was 2,068 children aged 11 to 18. Fieldwork was undertaken 
21st March – 1st April 2014.

There's reason to the non-smokers were just trying them out

.. as ASH data shows that even among teens continious use is extremely rare among non-smokers.
http://www.ashscotland.org.uk/media/6093/e-cigarettesbriefing.pdf
According to Minnesota Department of Health, "when a new product like e-cigarettes is spreading so rapidly, it is possible that some of the users in the past 30 days were just trying it out and may not continue using it."
http://www.health.state.mn.us/divs/chs/tobacco/teentobaccoexecsumm110614...
Do you have a better way to explain this discrepancy?

Some were, but not likely all

You should read more than the Executive Summary.  The full report states:
 
Students who have already used conventional tobacco products are the most likely to try a new product like e-cigarettes, but thousands of students who have no experience with conventional tobacco have been introduced to nicotine through e-cigarettes.

• In high school, 77.6 percent of students who have tried an e-cigarette have also tried conventional tobacco products, including 65.6 percent who have tried cigarettes.
• However, nearly one quarter of high school students who have tried e-cigarettes (22.4%) have never tried any conventional tobacco products. An estimated 15,300 Minnesota public high school students have tried an e-cigarette without ever having tried any tobacco product.
• 16.4 percent of high school students who have used an e-cigarette at least once in the past 30 days have never tried any of the conventional tobacco products.
Most students who have used an e-cigarette in the past 30 days are also using one or more of the conventional tobacco products.
• 60.1 percent of high school students who used an e-cigarette in the past 30 days also used conventional tobacco in the past 30 days, including 40.3 percent who smoked cigarettes.. 

ASH Data.

We all still await the full, peer reviewed publication of the ASH England data . . . . they confirmed to me yesterday that this is still in process.
Then, all can make a fully informed assessment of this data.
A colleague has asked for a copy of the presentation ASH made at PHE exibition: this is, unfortuantely, unavailable.
YouGov polls apparently have this usual methodolgy in the over-18s: https://yougov.co.uk/about/panel-methodology/
Did the methodology differ for this 11-18year old population? Awaiting feedback from YouGov on this . . . .
What exactly are the “incentives”? " Everyone taking part receives a modest cash incentive for doing so." according to YouGov. Are we sure they do not effect these on-line respondents?
YouGov as per link: "Once the survey is complete, the final data are then statistically weighted to the national profile of all adults aged 18+". But ASH data states:
“Based on the 84% of a sample of unweighted base of 2068 11-18 year olds, who had heard of electronic cigarettes”
Some http://tobaccoanalysis.blogspot.co.uk/2014/09/new-data-from-uk-show-that-despite.htmlhave have already taken the ASH data as "strong evidence". I think, personally, I would like to see the full paper and methodology, before making any firm conclusions . . . . I am sure that is what would be stated of data indicating a gateway effect??? 
David Bareham