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. 2018 Feb 26;11:1013–1023. doi: 10.2147/OTT.S154114

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© 2018 Yang et al. This work is published and licensed by Dove Medical Press Limited

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Flow chart of study selection.

Note: Copyright ©2009. Adapted from Moher D, Liberati A, Tetzlaff J, Altman DG. PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 2009;6(7):e1000097.³⁶

Abbreviation: PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-analyses.