Two more well-done studies show e-cig use associated with significantly less quitting smoking

Two papers were presented at the recent 2015 meeting of the Society for Research on Nicotine and Tobacco.  Both followed smokers over time and compared quitting cigarettes among smokers who use e-cigarettes with smokers who did not use e-cigarettes.  Both studies controlled for level of addiction among the smokers.  The first, based on a large national study, the Tobacco Use Supplement of the Current population survey, found that e-cigarette users were less than half as likely to have quit smoking (odds ratio = 0.44) than smokers not using e-cigarettes.  The other followed people in a smoking cessation program and found that e-cigarette users were about a third less likely to quit smoking (odd ratio = 0.68).
 
These results are consistent with the meta-analysis we published over a year ago as well as all but two (Beiner et al and Brown et al) of the other studies published since then (updated meta-analysis; another study showing less quitting).
 
It is time for  the FDA to clamp down on cessation claims made for e-cigarettes and state and local educational campaigns debunking this myth.  The most dangerous thing about e-cigarettes is that they keep people smoking cigarettes. 
 
E-CIGARETTE USE, SMOKING CESSATION AND CHANGE IN SMOKING INTENSITY IN THE 2010/2011 TUS-CPS LONGITUDINAL COHORT
 
Yuyan Shi*, Family Medicine and Public Health, University of California, San Diego; John Pierce, Moores Cancer Center, University of California, San Diego; Martha White, Moores Cancer Center, University of California, San Diego; Wilson Compton, National Institute on Drug Abuse, Kevin Conway, National Institute on Drug Abuse, Anne Hartman, National Cancer Institute; Maya Vijayaraghavan, Moores Cancer Center, University of California, San Diego; Karen Messer, Moores Cancer Center, University of California, San Diego
 
Background:  Electronic cigarettes (e-cigarettes) are heavily marketed, including for use as a smoking cessation aid.  There is limited data to address impacts on US smoking behavior.

Methods:  A representative cohort of US cigarette smokers (N=2,454) in 2010 Tobacco Use Supplement to the Current Population Survey (TUS-CPS) was re-interviewed 12 months later. Measures included ever-use of e-cigarettes for cessation or other reasons, use of pharmaceutical cessation aids (NRT or prescription medication), cigarette consumption level, and quitting history.  The association of e-cigarettes with attempted cessation, with changes in cigarette consumption, and with 30-day abstinence at follow-up was assessed using multivariate regression models, adjusting for demographics and baseline cigarette dependence level.

Results:  In this representative sample of US cigarette smokers, 11% (n=279) had ever used e-cigarettes and 42% (n=118) of ever-users reported use to help quit smoking.  Among smokers who made a quit attempt, the percent abstinent 30 + days at follow-up was 11.1% (95% CI 6.0,16.2)  for those who used e-cigarettes for cessation, compared to 17.8% (95% CI 8.8, 26.8) for those who used e-cigarettes for other reasons, and 21.6% (95% CI 19.4, 23.8)  for those who did not use e-cigarettes. For those who used an approved pharmaceutical aid 16.0% (95% CI 13.2, 18.8) were abstinent 30+ days at follow-up compared to 22.4% (95% CI 21.8, 25.0) of those who did not use such aids.  In an adjusted model, the use of e-cigarettes for cessation was associated with a 66% reduction in odds of 30 + day abstinence at follow-up (ORadj=0.44, 95%CI=0.24-0.79), and the use of pharmaceutical aids with a 33% reduction in odds of 30 + day abstinence  (ORadj=0.67, 95%CI=0.50-0.88), compared to use of neither aid. Among continuing smokers, only lighter smokers who used e-cigarettes to quit showed an association with reduced cigarette consumption. 

Conclusions:  US smokers who used e-cigarettes as a cessation aid were less successful at quitting than other smokers. The effect of e-cigarette use on smoking intensity was restricted to light smokers who used e-cigarettes for a quit attempt.
 
FUNDING: This project has been funded in whole or in part with Federal funds from the National Institute on Drug Abuse, National Institutes of Health, and the Food and Drug Administration, Department of Health and Human Services, under Contract No. HHSN271201100027C, UC Tobacco-Related Disease Research Program grants 21RT-0135, and National Cancer Institute grant No. 1R01CA172058-02.  CORRESPONDING AUTHOR: Yuyan Shi, PhD, Assistant Professor, University of California, San Diego, Family Medicine and Public Health, 9500 Gilman Dr, La Jolla, CA  92093-0622, United States, Phone: 858-534-4273, Email: [email protected]
 
ADOPTION OF E-CIGARETTES DURING TOBACCO DEPENDENCE TREATMENT IS ASSOCIATED WITH POORER QUIT OUTCOMES
Dmytro Pavlov, MSc*, Anna Ivanova, MPH, Sarwar Hussain, MSc, Peter Selby, MBBS, Laurie Zawertailo, PhD, Centre for Addiction and Mental Health and University of Toronto
 
Anecdotal evidence suggests that electronic cigarettes (e-cigs) are being used as a cessation aid by many smokers even though their safety and efficacy in this regard has yet to be sufficiently empirically determined. Other reports indicate that e-cigs are primarily used concurrently with traditional cigarettes. We examined baseline characteristics and 3-month outcomes of smokers who reported adopting e-cigs while enrolled in a smoking cessation program in their primary care clinic that provides up to 26 weeks of brief behavioural counseling and individualized dosing of nicotine replacement therapy at no cost. We hypothesized that concurrent e-cig use would interfere with the cessation treatment offered and result in poorer quit outcomes. Participants completed assessments and were asked about e-cig use at baseline and again at 3-months post-enrollment. Bivariate analysis was used to examine the association between e-cig adoption and baseline sample characteristics. Univariate logistic regression was used to examine the association between e-cig adoption and 3-month quit outcomes, as well as reduction in cigarettes smoked. The study included 3073 participants of whom 363 (11.8%) began using e-cigs in the first 3 months of treatment (but were not using at baseline). E-cig adopters were more likely to be younger and female, with no significant differences in baseline HSI scores, cigarettes per day, education level, employment status, income, quit confidence, and motivation to quit between e-cig adopters and non-adopters. At a 3-month follow-up, 50.8% of e-cig adopters were still using NRT. E-cig adopters were less likely to report being quit 3 months post enrollment (OR= 0.682, p=0.002, 95%CI=0.536-0.867), and had no significant effect in smoking reduction (OR=1.033, p=0.785, 95%CI=0.820-1.299). E-cig adoption seems to negatively affect cessation outcomes and provides no benefit as a harm reduction tool for clients receiving a combination of pharmacological and behavioural smoking cessation treatment in primary care settings. Many patients appear to be using e-cigs, NRT and traditional cigarettes concurrently, which may increase the risk of nicotine toxicity.
 
FUNDING: Support for this research was provided by the Ontario Ministry of Health and Long-Term Care, Health Promotion Branch
CORRESPONDING AUTHOR: Laurie Zawertailo, PhD, Clinical Scientist, Centre for Addiction and Mental Health, Nicotine Dependence Service, 175 College St., Room 212, Toronto, ON M5T1P7, Canada, 416-535-8501 x77422, Fax: 416-595- 8862, [email protected]