Marijuana smoking and asthma: a protocol for a meta-analysis

INTRODUCTION: Recent studies have raised the concern on the risk of asthma in marijuana smokers; however, the results remain controversial and warrant further investigation. With a growing number of marijuana smokers, examining the association between marijuana smoking and asthma and quantifying such association through meta-analysis have important implications for public health and clinical decision-making. In view of this, the present protocol aims to detail a comprehensive plan of meta-analysis on the association aforementioned. The findings are expected to strengthen the current knowledge base pertaining to the potential adverse effects of marijuana smoking on pulmonary health and to facilitate the development of prevention strategies for asthma. METHODS AND ANALYSIS: The MEDLINE/PubMed, Web of Science and EMBASE databases will be searched systematically from inception to 1 September 2021 to retrieve the relevant observational studies focusing on the association between marijuana smoking and asthma. Both unadjusted and adjusted effect sizes, such as OR, relative risk, HR and the corresponding 95% CIs will be extracted for pooled analyses. Heterogeneity and publication bias across the included studies will be examined. The Newcastle-Ottawa Quality Scale will be used to assess the quality and risk of bias. Statistical software Review Manager V.5.3 and Stata V.11.0 will be used for statistical analyses. ETHICS AND DISSEMINATION: Since no private and confidential patient data will be included in the reporting, approval from an ethics committee is not required. The results will be published in a peer-reviewed journal or disseminated in the relevant conferences. The study raises no ethical issue. OSF REGISTRATION NUMBER: 10.17605/OSF.IO/UPTXC.