Safety, efficacy and health impact of electronic nicotine delivery systems (ENDS): an umbrella review protocol

Background Electronic nicotine delivery systems (ENDS), commonly known as e-cigarettes or vapes, have witnessed a rise in popularity, particularly among the youth. Although they were initially introduced as an alternative to traditional smoking, the design and function of ENDS vary. The potential health effects of ENDS, especially in comparison to traditional cigarettes, are a matter of ongoing debate. Given the increasing number of clinical studies and systematic reviews on this topic, there exists a demand for an umbrella review that offers a comprehensive assessment. The goal of this study is to perform an umbrella review of systematic reviews and meta-analyses to assess the safety, efficacy, health implications and potential gateway effect associated with ENDS. Methods and analysis This umbrella review will adhere to the Joanna Briggs Institute (JBI) framework and the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. A planned literature search will be executed across databases such as OVID, PubMed/ MEDLINE, EMBASE, Cochrane Library and Web of Science. The inclusion criteria are systematic reviews that discuss ENDS and e-liquids in the context of safety, efficacy and health outcomes. The exclusion criteria include narrative reviews, non-systematic reviews and studies not in English. Quality of the selected studies will be evaluated using the AMSTAR V.2 Scale. An overlap assessment will be done using the Corrected Covered Area, and data synthesis will be presented both narratively and in tabulated forms Ethics and dissemination Ethics approval is not required for this study, as it does not involve the collection of original data. The results will be disseminated through peer-reviewed publication. The findings will offer crucial insights for stakeholders, policy-makers and the general public, underlining the health implications and the role of ENDS in tobacco cessation.