Longer-term use of electronic cigarettes when provided as a stop smoking aid: Systematic review with meta-analyses

Prev Med. 2022 Dec;165(Pt B):107182. doi: 10.1016/j.ypmed.2022.107182. Epub 2022 Aug 3.

Abstract

Moderate certainty evidence supports use of nicotine electronic cigarettes to quit smoking combustible cigarettes. However, there is less certainty regarding how long people continue to use e-cigarettes after smoking cessation attempts. We set out to synthesise data on the proportion of people still using e-cigarettes or other study products at 6 months or longer in studies of e-cigarettes for smoking cessation. We updated Cochrane searches (November 2021). For the first time, we meta-analysed prevalence of continued e-cigarette use among individuals allocated to e-cigarette conditions, and among those individuals who had successfully quit smoking. We updated meta-analyses comparing proportions continuing product use among individuals allocated to use nicotine e-cigarettes and other treatments. We included 19 studies (n = 7787). The pooled prevalence of continued e-cigarette use at 6 months or longer was 54% (95% CI: 46% to 61%, I2 86%, N = 1482) in participants assigned to e-cigarette conditions. Of participants who had quit combustible cigarettes overall 70% were still using e-cigarettes at six months or longer (95% CI: 53% to 82%, I2 73%, N = 215). Heterogeneity in direction of effect precluded meta-analysis comparing long-term use of nicotine e-cigarettes with NRT. More people were using nicotine e-cigarettes at longest follow-up compared to non-nicotine e-cigarettes, but CIs included no difference (risk ratio 1.15, 95% CI: 0.94 to 1.41, n = 601). The levels of continued e-cigarette use observed may reflect the success of e-cigarettes as a quitting tool. Further research is needed to establish drivers of variation in and implications of continued use of e-cigarettes.

Keywords: E-cigarette; Electronic cigarette; Longer term use; Quitting smoking; Smoking cessation; Systematic review.

Publication types

  • Meta-Analysis
  • Systematic Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electronic Nicotine Delivery Systems*
  • Humans
  • Nicotine / adverse effects
  • Smoking / epidemiology
  • Smoking Cessation*
  • Tobacco Smoking

Substances

  • Nicotine