Impact of non-menthol flavours in e-cigarettes on perceptions and use: an updated systematic review

Objectives Given the exponential increase in the use of e-cigarettes among younger age groups and in the growth in research on e-cigarette flavours, we conducted a systematic review examining the impact of non- menthol flavourede-cigarettes on e-cigarette perceptions and use among youth and adults. Design PubMed, Embase, PyscINFO and CINAHL were systematically searched for studies published and indexed through March 2018. Eligibility criteria Quantitative observational and experimental studies that assessed the effect of non- menthol flavoursin e-cigarettes on perceptions and use behaviours were included. Specific outcome measures assessed are appeal, reasons for use, risk perceptions, susceptibility, intention to try, initiation, preference, current use, quit intentions and cessation. Data extraction and synthesis Three authors independently extracted data related to the impact of flavoursin tobacco products. Data from a previous review were then combined with those from the updated review for final analysis. Results were then grouped and analysed by outcome measure. Results The review included 51 articles for synthesis, including 17 published up to 2016 and an additional 34 published between 2016 and 2018. Results indicate that non- menthol flavoursin e-cigarettes decrease harm perceptions (five studies) and increase willingness to try and initiation of e-cigarettes (six studies). Among adults, e-cigarette flavoursincrease product appeal (seven studies) and are a primary reason many adults use the product (five studies). The role of flavourede-cigarettes on smoking cessation remains unclear (six studies). Conclusion This review provides summary data on the role of non- menthol flavoursin e-cigarette perceptions and use. Consistent evidence shows that flavoursattract both youth and adults to use e-cigarettes. Given the clear findings that such flavoursincrease product appeal, willingness to try and initiation among youth, banning non- menthol flavoursin e-cigarettes may reduce youth e-cigarette use. Longitudinal research is needed to examine any role flavoursmay play in quit behaviours among adults.