Thursday, 27 July 2017

Another study shows that vaping helps people quit smoking

A study published in the BMJ today will have the usual anti-vaping fanatics howling at the moon. It found that vapers were much more likely to attempt to quit smoking than those who don't vape, and that they are 73 per cent more likely to succeed in quitting smoking when they do. It also finds a significant increase in smoking cessation in the USA that coincides with the rise of vaping.

Anti-vaping throwbacks will no doubt say that correlation does not equal causation, but the authors examine two possible alternative explanations for the decline in the smoking rate and find them wanting...

First, in 2009 there was an increase in federal tobacco tax. The national cigarette tax increased by 158%, resulting in an immediate reduction in cigarette uptake among US adolescents. In our study we found a small but statistically significant increase in quit attempts among US adults, from 39.9% in 2006-07 to 41.4% in 2010-11 (fig 2, top panel). However, the total cessation rate did not change: 4.5% for both surveys (fig 2, bottom panel). Thus the effect of the 2009 federal tax on quitting by adult smokers, if there was an immediate one, was no longer detectable by 2010-11. This lack of change in smoking cessation under such a dramatic tax increase accentuates the difficulty in improving quit rates at the population level. 

Second, since 2012 there have been annual, national media campaigns aimed at increasing quit rates among adult smokers. The TIPS from Former Smokers campaign used evocative television spots showing the serious health consequences of tobacco use. This campaign, running from nine to 20 weeks in any given year, reached a large segment of the smoking population. A national survey after the first round of the campaign found that 78% of smokers saw at least one media spot. By 2015, there had been four rounds of the campaign. Surveys found a statistically significant increase in quit attempts, and the cessation rate of those who made a quit attempt was estimated to be between 5.7% and 6.1%.

In the present study we found statistically significant increases in both quit attempt and cessation rates from 2010-11 to 2014-15. This period coincided with the TIPS campaign and the dramatic increase in e-cigarette use.

Could TIPS alone explain the increase? Given the reach of the first TIPS campaign, after four rounds it was expected to reach most US smokers by 2014-15. However, the majority of smokers did not appear to change their quitting behavior: smokers who did not use e-cigarettes were the majority (77%) in 2014-15. Neither their attempt rate nor the annual cessation rate was statistically different from that of all smokers in 2010-11 (fig 1). It was e-cigarette users in 2014-15 who showed a dramatically higher quit attempt rate and a higher cessation rate. 

The authors caution against attributing all of the difference in cessation rates to vaping because it is possible that those who are most committed to quitting are more likely to use e-cigarettes. However, this study is hardly the first to find a significantly higher rate of quitting among vapers and randomised controlled trials have found the same thing. Indeed, the quit rate among vapers in this study is more modest than has been found in most other studies, but it's published in the BMJ so is getting more attention.

The authors are from California so it is brave of them to publish a study that not only shows that vaping works but that the favoured policies of the tobacco control cabal don't. As a final dig in the ribs they conclude their study by saying:

We found that e-cigarette use was associated with an increased smoking cessation rate at the level of subgroup analysis and at the overall population level. It is remarkable, considering that this is the kind of data pattern that has been predicted but not observed at the population level for cessation medication, such as nicotine replacement therapy and varenicline.

They'll probably never work again.

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