Nicotine e-Cigarettes as a Strategy for Smoking Cessation

Is use of nicotine e-cigarettes an effective strategy for tobacco smoking cessation?

Use of nicotine e-cigarettes increases tobacco smoking cessation rates compared with use of nicotine replacement therapy (NRT), non-nicotine e-cigarettes, behavioral support only, and no support. (Strength of Recommendation [SOR]: A, Cochrane review, systematic review, meta-analysis of five randomized controlled trials [RCTs], and a large RCT.) Nicotine e-cigarettes are as effective as varenicline (Chantix) for tobacco smoking cessation at 26 weeks, but the effect may wane over time. (SOR: B, single-site RCT.)

A 2024 Cochrane review analyzed 88 studies, including 47 RCTs, eight randomized crossover trials, and 33 uncontrolled cohort studies (N = 27,235). The review evaluated the effectiveness of nicotine e-cigarettes for tobacco smoking cessation vs conventional NRT (eg, nicotine gums, nicotine transdermal patches), varenicline, non-nicotine e-cigarettes, heated tobacco products, behavioral support only, and no support. The adults involved in the review smoked cigarettes and had varying levels of motivation to quit smoking.¹

Patients in the RCTs were randomized to receive nicotine e-cigarettes or a control option, such as conventional NRT, non-nicotine e-cigarettes, behavioral support only, or no intervention. The review compared the following interventions: nicotine e-cigarettes with NRT, with non-nicotine e-cigarettes, with behavioral support only, or with no support. Primary outcomes were tobacco smoking cessation at least 6 months from the start of the intervention and number of patients reporting any adverse effect or serious adverse effect, respectively, at 1 week or longer.

Cessation rates were higher in patients randomized to nicotine e-cigarettes compared with those randomized to NRT (seven studies; n = 2,544; risk ratio [RR] = 1.59; 95% CI, 1.30–1.93). Nicotine e-cigarette use also increased quit rates compared with non-nicotine e-cigarette use (six studies; n = 1,613; RR = 1.46; 95% CI, 1.09–1.96). Additionally, there were higher cessation rates for patients randomized to nicotine e-cigarettes compared with behavioral support only or no support (nine studies; n = 5,024; RR = 1.88; 95% CI, 1.56–2.25). However, due to issues with risk of bias, the higher quit rate compared with behavioral support alone was supported by low-certainty evidence.

In 2023, a systematic review and meta-analysis of five RCTs (N = 3,253) compared nicotine e-cigarettes with conventional tobacco smoking cessation therapies (eg, NRT, bupropion, varenicline, behavioral counseling alone). The review included only trials with adult cigarette smokers. The studies involved patients who were randomized to nicotine e-cigarette use for a treatment period of at least 10 weeks and a follow-up duration of at least 6 months. RCTs had to report at least one biochemically validated end point to verify smoking cessation (eg, inhaled carbon monoxide, serum cotinine measurement).²

Use of nicotine e-cigarettes increased tobacco smoking cessation compared with use of conventional therapies (RR = 1.77; 95% CI, 1.29–2.44). Nicotine e-cigarettes were associated with higher smoking abstinence rates compared with non-nicotine e-cigarettes (RR = 1.56; 95% CI, 1.13–2.15). Two trials had a high risk of bias due to missing outcomes data. The longest follow-up of smoking cessation included in this meta-analysis was 12 months; thus, data on long-term effectiveness, adverse events, and effects of nicotine use disorder were limited.