A Systematic Review and Meta-analysis of Associations between E-cigarette Use among Nontobacco Users and Combustible Cigarette Smoking Intentions

Objectives: The potential association between e-cigarette use and cigarette smoking persists as an important public health issue. Strictly adhering to AMSTAR 2 and PRISMA guidelines, our evidence synthesis examined the association between e-cigarette use among non-tobacco users and the intention to smoke cigarettes.Methods: We searched 3 databases from January 1, 2007 to April 26, 2023 and screened search results according to the PICOS review method. Results: We synthesized 20 demographically adjusted studies on smoking intention, including related outcome measures of willingness/openness/curiosity to smoke cigarettes and susceptibility to smoke cigarettes. All studies suggested a significant association between e-cigarette use and intention to smoke according to measures of experimental e-cigarette use (i. e., ever or current use, and not established and/or regular use). Conclusions: Studies defining e-cigarette use according to measures of established and/or regular use, and that adequately controlled for specific confounding variables representing common liabilities between e-cigarette use and cigarette smoking are limited in the evidence base. Thus, currently there is limited evidence to support an association between e-cigarette use and the intention to smoke cigarettes. Future research should apply measures of regular and/or established e-cigarette use that adequately account for confounding variables that consider common liabilities between e-cigarette use and cigarette smoking. Doing so would enable the findings to support robust determinations regarding any potential association between e-cigarette use and the intention to smoke cigarettes.