Study links increased e-cigarette use to increased smoking quit rates in U.S.

The recent increase in the use of electronic cigarettes may have led to higher smoking cessation rates in the U.S., a recent study found.

To examine whether the increase in e-cigarette use in the U.S. (which began around 2010 and substantially increased by 2014) was associated with a change in the population's overall smoking cessation rate, researchers assessed five rounds of the U.S. Current Population Survey-Tobacco Use Supplement: 2001-2002, 2003, 2006-2007, 2010-2011, and 2014-2015.

Researchers compared smoking cessation rates of survey respondents who reported smoking cigarettes in the 12 months before the survey. Each survey had between 20,000 and 40,000 respondents who smoked, with declining sample sizes over time, largely due to declining smoking prevalence. Primary outcomes were the rate of attempts to quit smoking and the rate of successfully quitting smoking (defined as having quit for at least three months).

Results were published on July 26 by The BMJ.

Of 161,054 respondents in the 2014-2015 survey, 22,548 currently smoked and 2,136 had recently quit. Of these, 38.2% and 49.3%, respectively, had tried e-cigarettes, and 11.5% and 19.0%, respectively, currently used them (every day or some days).

Those who used e-cigarettes within the past year were more likely than nonusers to attempt to quit smoking (65.1% vs. 40.1%; difference, 25.0% [95% CI, 23.2% to 26.9%]) and to succeed in quitting (8.2% vs. 4.8%; difference, 3.5% [95% CI, 2.5% to 4.5%]). In 2014-2015, the overall population cessation rate was significantly higher than in 2010-2011 (5.6% vs. 4.5%; difference, 1.1% [95% CI, 0.6% to 1.5%]), as well as in all other survey years (range, 4.3% to 4.5%).

The authors noted limitations to the study, such as the recall biases related to self-report and the inability to compare outcomes between e-cigarette users and users of traditional pharmacotherapy.

In addition, two major interventions occurred at the national level between the first and most recent surveys: an increase in the federal tobacco tax in 2009 and pervasive smoking-cessation media campaigns that began in 2012. It is likely that these factors, along with the increased use of e-cigarettes, “worked synergistically to produce the first substantial increase in population cessation in the US in the past 15 years,” the authors wrote.

An accompanying editorial highlighted the need to fill information gaps about e-cigarettes, such as their long-term safety and the distribution of their effect on smoking cessation among different population groups.

Both this study and a study in the United Kingdom with similar results assessed data from populations in countries with relatively liberal regulatory approaches toward e-cigarettes, the editorial noted.

“The research … suggests that where such permissive approaches to e-cigarettes exist—ones that enable smokers to have ready access to products that deliver nicotine effectively, at a price lower than that of tobacco cigarettes—then substantial numbers of smokers will make the transition away from smoking, and a substantial population benefit can result,” the editorialist wrote.

In related news, the FDA on July 28 announced a new plan to regulate tobacco that may increase the availability of e-cigarettes. The agency is considering the possibility of lowering nicotine levels in combustible cigarettes to nonaddictive amounts, as well as extending the deadline for manufacturers to submit product review applications for newly regulated combustible and noncombustible tobacco products that were on the market as of Aug. 8, 2016. It remains unclear which regulations may result from this initial plan.