Respiratory and Cardiovascular Health Effects of E-Cigarette Substitution: Protocol for Two Living Systematic Reviews

Background Despite the clear risks of tobacco use, millions of people continue to smoke. Electronic nicotine delivery systems (ENDS), commonly called e-cigarettes, have been proposed as a substitute for those who are unwilling or unable to quit. Current systematic and narrative reviews on the health effects of ENDS use, respiratory and cardiovascular effects in particular, have come to differing conclusions.

Objective The purpose of our two systematic reviews is to critically assess and synthesize the available human studies on the respiratory and cardiovascular health effects of ENDS substitution for people who smoke. The primary goal is to provide clinicians with evidence on the health effects of ENDS substitution to inform their treatment recommendations and plans. The twin goal is to promote the health literacy of ENDS users with facts on the health effects of ENDS. A secondary goal is to develop policy briefs to provide governmental bodies with a preliminary assessment of the potential public health impacts of ENDS.

Methods These two reviews will be living systematic reviews. The systematic reviews will be initiated with a baseline review. Studies will be evaluated with the JBI quality assessment tools and a checklist of biases drawn from the Centre for Evidence Based Medicine’s Catalogue of Bias. A narrative synthesis is planned due to the heterogeneity of data. A search for recently published studies will be conducted every three months, and an updated review published every six months for the duration of the project or possibly longer.

Results The baseline and updated reviews will be published in a peer review journal. The review findings will be reported in a white paper for clinicians, a fact sheet for people who use ENDS, and country-specific policy briefs.

Conclusions The substitution of ENDS for cigarettes is one of the ways to potentially reduce the risks of smoking. Clinicians and their patients need to understand the potential benefits and possible risks of substituting ENDS for cigarettes. Our living systematic reviews seek to highlight the best and most up-to-date evidence in this highly contentious and fast-moving field of research.

Competing Interest Statement

RO is supported by a contract with ECLAT, Srl. ECLAT has received funding from the Foundation for a Smoke-Free World. She declares no conflicts of interest. MQ has a grant from Foundation for a Smoke-Free World, outside the submitted work, for the project Pakistan Tobacco Economics Research and Dissemination. She declares no conflict of interest. RP has received has received lecture fees and research funding from Pfizer, GlaxoSmithKline, CV Therapeutics, NeuroSearch A/S, Sandoz, MSD, Boehringer Ingelheim, Novartis, Duska Therapeutics, and Forest Laboratories. He has served as a consultant for Pfizer, Global Health Alliance for treatment of tobacco dependence, CV Therapeutics, Boehringer Ingelheim, Novartis, Duska Therapeutics, ECITA (Electronic Cigarette Industry Trade Association, in the UK), Arbi Group Srl., and Health Diplomats. He has served on the Medical and Scientific Advisory Board (MSAB) of Cordex Pharma, Inc., CV Therapeutics, Duska Therapeutics Inc, Pfizer, and PharmaCielo. Lecture fees from a number of European EC industry and trade associations (including FIVAPE in France and FIESEL in Italy) were directly donated to vaper advocacy non-profit organizations. RP is the founder of the Center for Tobacco prevention and treatment (CPCT) at the University of Catania and the Center of Excellence for the acceleration of Harm Reduction (CoEHAR) at the same University, which has received support from Foundation for a Smoke Free World to conduct 8 independent investigator-initiated research projects on harm reduction. RP is currently involved in the following pro bono activities: scientific advisor for LIAF, Lega Italiana Anti Fumo (Italian acronym for Italian Anti-Smoking League), the Consumer Advocates for Smoke-free Alternatives (CASAA) and the International Network of Nicotine Consumers Organizations (INNCO); Chair of the European Technical Committee for standardization on Requirements and test methods for emissions of electronic cigarettes (CEN/TC 437; WG4).