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. 2020 Jan 9;16(8):1969–1980. doi: 10.1080/21645515.2019.1698901

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© 2019 The Author(s). Published with license by Taylor & Francis Group, LLC.

This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way.

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Figure 1. — PRISMA Flow diagram. Legend: Number of studies identified by search strategy, number of studies excluded and included during primary and secondary (full -text) screening, and final number of studies included”.