How shaky are the twin pillars of the case for e-cigarettes?

The central arguments made for the importance of electronic cigarettes (e-cigarettes) are that they are an exceptionally good way to quit smoking and that they represent trivial risk to health compared to the stratospheric risks of smoking. (Australian data published last year from the very large 45 and Up cohort study found that up to two in three long-term smokers were likely to die from a smoking-caused disease.)

Two just-released papers promise to further ignite debate about these two central pillars of the case being made for these putative harm-reduction products.

A systematic review of all studies examining whether smokers who use e-cigarettes quit smoking at a different rate to those who don’t has been published today in Lancet Respiratory Medicine. The review identified 38 studies, with 20 having control groups.

Pooling these, they found that the odds of quitting cigarettes were 28% lower in those who used e-cigarettes compared with those who didn’t.

Of course, not all vapers are using e-cigarettes to quit. Many use them to just cut down, often in the erroneous belief that reducing the number of cigarettes smoked daily will reduce harm. I summarised and linked to four cohort studies that demonstrate this folly in a recent lengthy Conversation piece.

So if many smokers are not even trying to quit with e-cigs, some might argue that that there should be no expectation that they would.

The problem with that assumption is that we have an increasing understanding that many smokers do not plan to try to quit, but rather do it quite spontaneously.

For example, in this 2006 paper on a national sample of English smokers, 48.6% of smokers reported that:

their most recent quit attempt was put into effect immediately the decision to quit was made. Unplanned quit attempts were more likely to succeed for at least six months: among respondents who had made a quit attempt between six months and five years previously the odds of success were 2.6 times higher (95% confidence interval 1.9 to 3.6) in unplanned attempts than in planned attempts.

In this new review, the authors consider both smokers who were trying to quit by using e-cigs and those who were not. They found that:

the association of e-cigarette use with quitting did not significantly differ among studies of all smokers using e-cigarettes (irrespective of interest in quitting cigarettes) compared with studies of only smokers interested in cigarette cessation.

In other words, regardless of whether a smoker using e-cigarettes was planning to quit or not, there was no difference in whether they did.

The authors note that pooled estimates in previous reviews of e-cigarettes’ usefulness in smoking cessation did not include a comparison to other means of stopping besides e-cigarette use, so they cannot be used to determine whether e-cigarettes are associated with greater cigarette abstinence than quit rates being obtained in current practice.

They speculate that the poorer performance of e-cigs across all studies when pooled may mirror the changing situation of nicotine replacement therapy:

Data from the large population-based California Tobacco Surveys, showed that nicotine replacement therapy (NRT) was associated with long-term success in quitting cigarettes when available by prescription only, but this association was lost when NRT became available over-the-counter.

This view should challenge those calling for the greatest possible ease of obtaining e-cigarettes.

In a second paper, globally renowned toxicologists Robert Combes and Michael Balls have written a critical commentary stimulated by the 2015 publication of Public Health England’s (PHE) report on e-cigarettes.

The PHE report has already attracted critical commentary in both the Lancet and the BMJ about the provenance of a key and globally telegraphed statement in the report that e-cigarettes were about “95% less harmful” than cigarettes.

This figure was conjured as a “best estimate” by a heavily criticised consensus meeting of 12 people. Six of these were subsequent signatories to the 53 signature letter to Dr Margaret Chan at the World Health Organization calling for minimal regulation. Six had no research track record or experience in tobacco control whatsoever. Two had financial ties to the tobacco or e-cigarette industries (see here and here). There was no transparency about how this group had been selected and questions remain about the role of the tobacco industry in its funding.

Combes and Balls describe a recommendation from the PHE report that e-cigarettes be made available to smokers through the UK’s National Health Service as:

a classic example of the temptation of short-term gain irrespective of the possibility of long-term pain.

Pulling no punches, they argue that “lack of safety data and the resulting inability to perform any sort of risk assessment of the type normally undertaken for consumer products” makes the PHE’s recommendation “in the light of current knowledge [about e-cigarette safety] a reckless and irresponsible suggestion.”

Their commentary details numerous examples of significant absences of potential safety concerns in the PHE report, which appear to have been bypassed in light of what they call a well-meaning but misguided effort to propose a quick fix.

It is a paper that should be read by anyone who believes that the science is already settled on e-cigarettes.

Many e-cigarettes advocates are utterly convinced that vaping is highly effective at getting people off smoking, and of negligible health risk. It would be wonderful if they were right on both counts. These two papers should serve as a major amber light to such unbridled enthusiasm.

The very latest update of the Smoking in England project provides data that show that 68.2% of people who vape in England still continue to smoke (dual use):

And very worryingly, the percentage of smokers in England making a quit attempt in the last year is at the lowest point since 2007:

As these Conversation authors discussed, vaping may be holding many smokers back from quitting. At the population level, such an effect needs to balanced against the impact e-cigarettes may be having cessation so that we get an understanding of the net costs and benefits of e-cigarettes.

Some vaping advocates valiantly insist that their mission of “saving a billion lives” this century from tobacco deaths is so important that e-cigarettes should be able to by-pass all of the regulatory oversights that sensibly apply to chemicals and pharmaceuticals everywhere but in chaotic nations where anything goes and where consumers are unprotected from exploitation by manufacturers making misleading claims for useless and often dangerous products.

No one heroically claiming an AIDS or cancer cure on the same level of flimsy evidence of safety and efficacy that Combes and Balls point to with the current evidence base would get even a toe in the door to be allowed to sell and advertise such products.

If e-cigarettes are as safe and effective as their enthusiasts claim for them, let us all see the high quality data. We all want that, surely?

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