The Evidence-Based Advantages of E-Cigarettes: A Study Review

Published on May 22, 2019

While both Public Health England and the National Academies of Sciences, Engineering and Medicine acknowledge that completely switching from combustible cigarettes to non-combustible products, such as e-cigarettes, exposes users to substantially less toxicants and dangerous chemicals, there remains lacking support for their use as a quitting tool. For example, NASEM’s report concludes that: “Overall, there is limited evidence that e-cigarettes may be effective aids to promote smoking cessation.” On the contrary, however, there is evidence to suggest that e-cigarettes are growing in popularity as a quit tool.

Accordingly, in an effort to further probe the role of e-cigarettes in initiating cessation and/or maintaining abstinence, Peter Hajek and colleagues developed a randomized trial to compare smoking cessation and abstinence among populations that use traditional nicotine replacement therapies (NRT) versus those who use e-cigarettes (EC).

In terms of participant selection, subjects were accepted into the study if they were currently not using any products and had no strong preference for use of either nicotine replacement therapies or electronic cigarettes as a quit method. After being accepted, participants were randomized to receive either an e-cigarette or an NRT of their choice (the nicotine patch was used by 84 percent of participants generally along with a fast-acting oral product) and asked simply to adhere to their treatment group (EC or NRT). Participants were then asked about smoking status at 4, 26 and between 26-52 weeks—52-week abstinence was biochemically verified at the final visit.

With respect to findings, overall, the e-cigarette group had significantly higher abstinence rates at all time points than those in the nicotine replacement therapy group. For example, at the conclusion of the study (52 weeks), the abstinence rate was 18 percent for those in the EC group and only 9.9 percent for those in the NRT group. At the 4-, 26- and between 26-52-week points, it was approximately 44, 35 and 21 percent for the EC group and 30, 25 and 12 percent for NRT.

Moreover, even participants in the EC group who were unable to achieve abstinence had higher rates of reduction in cigarettes smoked (biochemically verified as a 50 percent reduction or more) than those in the NRT group (12.8 vs. 7.4 percent respectively). At the conclusion of the study, participants in the EC group also had a much higher rate of treatment adherence than those in the NRT group at 39.5 and 4.3 percent respectively.

While these numbers overwhelmingly suggest that ECs have the potential to be more effective quitting tools than NRTs, some limitations in the study’s methodology suggest that their full potential as a cessation tool may not even yet be realized. For example, at four weeks, 56 percent of participants in the EC group were not abstinent and although statistically significant, the urge to smoke in the first four weeks was only marginally lower for those in the EC group versus those in the NRT group. However, this may have been an unintentional result of the study’s design. Those in the EC group, were given an initial supply that consisted of a 30 ml bottle at 18mg/ml and were then encouraged to experiment with nicotine concentrations in subsequent refills. While supplementary data indicated that most participants moved to lower and not higher concentrations as the study progressed, it stands to reason that if a higher concentration had been delivered initially, it may have prevented drop out early on.