Risk of smoking relapse with the use of electronic cigarettes: A systematic review with meta analysis of longitudinal studies Vaping Study Retracted: Massive Fraud Exposed! #shorts A systematic review and meta analysis of the association between e cigarette use among non tobacco users and initiating smoking of combustible cigarettes Harm Reduction Journal Springer Nature Link The impact of electronic cigarette use on chronic obstructive pulmonary disease: A systematic review and meta analysis Respiratory Medicine While vaping is not risk free, it is less harmful than tobacco Our World in Data