major review of global smoking cessation research has found that e-cigarettes containing nicotine appear to help people quit smoking more effectively than several other commonly used methods. These include nicotine replacement therapy (nicotine patches, gum, lozenges, etc.), non-nicotine e-cigarettes, and behavioral support programs.
The research combined evidence from multiple systematic reviews to provide a clearer picture of how well different smoking cessation tools work. Researchers analyzed findings from fourteen systematic reviews published between 2014 and 2023.
Higher-Quality Studies Favor Nicotine Vapes
The strongest and most reliable reviews consistently showed better smoking cessation outcomes among people using nicotine e-cigarettes. Lower-quality reviews produced less consistent and less precise results. When researchers focused only on the highest-quality evidence, nicotine e-cigarettes repeatedly performed better than nicotine replacement therapy, non-nicotine e-cigarettes, and other comparison methods.
Evidence Gaps Still Need More Research
As part of the project, researchers also developed an ‘Evidence and Gap Map’ (EGM) to identify areas where scientific evidence is still lacking. The review found that there are currently no high-quality systematic reviews directly comparing nicotine e-cigarettes with cytisine, bupropion, or nicotine pouches.
Evidence comparing nicotine e-cigarettes with varenicline is also very limited. Researchers found only one small study on that comparison, and it was considered to have a high risk of bias.
Questions Remain About Long-Term Safety
The EGM also found that evidence regarding serious adverse events linked to e-cigarettes remains inconclusive. In addition, most of the available research data comes from high-income countries.
Researchers say future studies on e-cigarettes and smoking cessation should continue tracking possible serious adverse events while also expanding research efforts in low-and middle-income countries.
