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. 2021 Oct 20;9:689123. doi: 10.3389/fpubh.2021.689123

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Copyright © 2021 Wang, Shi, Guan, Xu, Liu and Li.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

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Flow of information through different phases of the systematic review according to the PRISMA statement [^#Detailed search results: PubMed Database (n = 202), Web of Science Database (n = 377), EBSCO host Database (n = 113), The Cochrane Library Database (n = 286), ScienceDirect Database (n = 108)].