Use of electronic-cigarettes was associated with a lower rate of smoking cessation at 6 months among recently hospitalized smokers who said they planned to quit, compared with non-users in a secondary analysis of a large randomized trial.
Six months after discharge, the participants who used e-cigarettes had a lower incidence of smoking cessation than those who did not use e-cigarettes, wrote Nancy Rigotti, MD, director of the Tobacco Research and Treatment Center of Massachusetts General Hospital in Boston, and colleagues.
Action Points
- Electronic-cigarette (e-cig) use was associated with a lower rate of smoking cessation 6 months after hospital discharge among recently hospitalized smokers who said they planned to quit, in a secondary observational data analysis of a large, randomized trial.
- Note that almost 70% of the subjects who used e-cigarettes said they did so to help them quit combustible cigarettes, but the frequency of use ranged from daily to just once a week, and the data show only association but not causation.
In an analysis of 237 propensity score-matched pairs, 10.1% of e-cigarette users had quit smoking at 6 months, versus 26.6% of non-users (risk difference -16.5%; 95% CI -23.3% to -9.6%).
Three months after hospital discharge, 28% the 1,357 study participants reported e-cigarette use, and of those, less than half said they used e-cigarettes regularly -- a low rate that could have affected the findings, Rigotti and colleagues wrote.
The observational analysis is published online in
"We found that patients who used e-cigarettes were actually less likely to succeed in quitting compared to those who did not, which is the reverse of what we might expect to see if e-cigarettes help people quit," Rigotti told MedPage Today.
"But a big caveat is that we don't know how they were using them. The e-cigarette users may have been the people who were having the most trouble quitting."
Rigotti noted that while almost 70% of the study participants who used e-cigarettes said they were doing so to help them quit combustible cigarettes, the frequency of use ranged from daily to just once a week.
"I think the message of this paper is that using e-cigarettes infrequently or using them with cigarettes is just not an effective way to quit smoking. Many of these people didn't even use e-cigarettes once a day. People who have success with [approved] smoking-cessation medications use them regularly. That is probably how e-cigarettes need to be used if they are going to be effective."
The analysis included participants in the randomized , conducted to assess the efficacy of a post hospital-discharge smoking-cessation intervention. All 1,357 participants received tobacco-cessation counseling while hospitalized, and were randomized to receive a tobacco treatment recommendation consisting of instructions on accessing a telephone quit-line and medication recommendations (controls) or the same intervention with free access to a smoking-cessation medication.
Self-reported e-cigarette use was assessed 1 month and 3 months after hospital discharge, and biochemically validated tobacco abstinence was assessed 6 months after discharge.
The association between e-cigarette use and quitting varied between intervention patients given free access to medications (7.7% versus 29.8%; risk difference, -22.1%; 95% CI, -32.3% to -11.9%) and control patients (12% versus 24.1%, 95% CI, -21.2% to 2.9%) (P for interaction = 0.143).
"Because of the study's observational design, in which e-cigarette use was self-selected, unmeasured confounding could explain the findings, and a causal relationship cannot be inferred from these data," the researchers cautioned, adding, however, that E-value calculation indicated that only a very strong unmeasured confounder could explain the findings.
Other study limitations included the lack of information on e-cigarette type and lack of detailed information on frequency of use.
"Despite the limitations inherent in its observational design, this study illustrates how e-cigarettes, which are widely available commercially, are being used in a common clinical situation (a cessation attempt after hospitalization)," the researchers wrote.
"In this setting, the use of e-cigarettes intermittently and concurrently with other cessation aids did not seem to aid quitting and may have hampered it. The possibility remains that e-cigarettes can promote tobacco cessation if they are used regularly and as a complete replacement for cigarettes, which is how conventional cessation medications are recommended for use. Future research, particularly randomized controlled trials, is needed to address this critical question."
Disclosures
Funding for the research was provided by the National Heart, Lung, and Blood Institute.
Rigotti reported a grant and non-financial support from Pfizer and personal fees from UpToDate outside the study; one co-author reported personal fees from UpToDate unrelated to the study, and another co-author reported personal fees from Pfizer outside the study.
Primary Source
Annals of Internal Medicine
Rigotti NA, et al. "Association of e-cigarette use with smoking cessation among smokers who plan to quit after a hospitalization" Ann Intern Med 2018; DOI: 10.7326/M17-2048.