Published: 12 October 2020

Electronic cigarette and smoking cessation. An evidence review

This systematic evidence review assessed the efficacy and safety of electronic cigarettes (e-cigarettes) and heat-not-burn products in helping people who smoke to achieve abstinence at 24 or 26 and 52 weeks using randomised controlled trials (RCTs). Seven RCTs met the inclusion criteria for efficacy of e-cigarettes in helping people quit smoking and nine provided data for safety. There were no RCTs that met the inclusion criteria for the question on efficacy of heat-not-burn tobacco products in helping people quit smoking. Two studies reported adverse event data for heat-not-burn tobacco products.

The systematic review and network meta-analysis of e-cigarettes versus therapies usually given for smoking cessation showed that there is no evidence of a difference in effect on incidences of smoking cessation. There is a low-level of certainty in these results due to low successful event rates and high rates lost to follow-up in all studies. We identified respiratory adverse events, including shortness of breath and cough, that appeared to be higher in e-cigarette users, but in the main, RCT evidence on adverse events is lacking. The long-term data on e-cigarettes, in line with European Medicines Agency recommendations, are limited for both smoking cessation and adverse events, and further large-scale research using a standardised product to decrease uncertainly at the 1-year timepoint and beyond is needed.

We found no evidence from RCTs on efficacy of heat-not-burn products for smoking cessation compared with current standard care, and insufficient evidence on the safety of heat-not-burn tobacco products from RCTs.


  • Joan Quigley
  • Helen Kennelly
  • Caitriona Lee
  • Doireann O'Brien
  • Michelle Williams
  • Anne McCarthy
  • Jean Long

Publication (PDF, 1 MB)

Publication (PDF, 1 MB)

Health Research Board
Health Research Board
Place of publication