A large, multi-centre randomized clinical trial of adults motivated to quit smoking found that using nicotine e-cigarettes plus counseling was more than twice as effective as counseling alone at sustaining abstinence after twelve weeks of treatment. However, after twenty-four weeks, the difference between the two groups was no longer significant. In contrast, among those who used non-nicotine e-cigarettes plus counseling, the quit rate was significantly higher after twenty-four weeks when compared with counseling alone, but not at twelve weeks. This, according to findings published today in JAMA.
The study, known as the E3 Trial (Evaluating the Efficacy of E-Cigarette Use for Smoking Cessation), involved 376 participants across Canada at seventeen sites. They were recruited between November 2016 and September 2019, with follow-up completed in September 2020. The participants averaged fifty-two years of age and had been smoking roughly 20 cigarettes a day for as long as three decades. Due to a manufacturing delay of the e-cigarettes used in the trial, the study was terminated earlier than originally planned.
Abstinence was significantly greater for nicotine e-cigarettes plus counseling (21.9%) compared with counseling alone (9.1%) at twelve weeks; but not at twenty-four weeks (17.2% vs 9.9%, respectively). Abstinence for non-nicotine e-cigarettes plus counseling was not significantly different from counseling alone at twelve weeks (17.3% vs. 9.1%), but was significantly greater at twenty-four weeks (20.5% vs 9.9%).
Another notable finding was a significant reduction in mean self-reported daily cigarette consumption from baseline for participants randomized to nicotine e-cigarettes plus counseling compared to counseling alone at twelve weeks (-12.6 vs -7.0) and 24 weeks (-10.7 vs -5.5). Reduction in mean self-reported daily cigarette consumption was also significant among participants randomized to non-nicotine e-cigarettes plus counseling compared to counseling alone at twelve weeks (-10.6 vs -7.0) and twenty-four weeks (-9.1 vs -5.5).
“The health benefits of smoking reduction (vs complete abstinence) are controversial,” the authors of the study wrote. “However, studies have shown that individuals who reduce their daily cigarette consumption are more likely to successfully quit in future attempts.” This is important because it is easier to withdraw from a habit that involves fewer cigarettes.
“Although e-cigarettes may not lead to immediate cessation of smoking, they can be a part of a transition process that may require some time to take effect,” explained Dr. Mark Eisenberg, a senior investigator and cardiologist with the Lady Davis Institute at the Jewish General Hospital in Montreal, and the study leader. “We recognize that most smokers will make multiple attempts to quite before succeeding, which is testament to the power of this addiction.”
Data from the United States have shown that more than 70% of smokers who report having made an effort to quit return to smoking even after using at least five weeks of pharmacologic and/or behavioural therapy. Despite the well-established risks of smoking, it continues to contribute to the death of more than 37,000 Canadians annually. Moreover, only 10 to 20% of smokers will succeed in quitting using currently approved cessation therapies, including nicotine patches, gum, and counseling.
The E3 Trial was designed to ascertain whether e-cigarettes might be a more effective aid to achieve lasting smoking cessation. “The study showed that some people, many of whom have tried other methods unsuccessfully, have positive results with e-cigarettes,” said Dr. Eisenberg, a Professor of Medicine at McGill University. “This is indicative that there is no one magic bullet. The efficacy of a therapeutic approach is dependent on what may best suit a particular individual.
“The single most reversible cause of mortality in Canada is smoking,” he goes on. “While there are still unanswered questions concerning the safety of long-term use of e-cigarettes, we believe that they are likely a better alternative than continued smoking of conventional cigarettes.”
