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. 2016 Apr 16;5:64. doi: 10.1186/s13643-016-0238-0

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© Hoffman et al. 2016

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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Fig. 1 — PRISMA flow diagram (in process). Legend:ASSIAApplied Social Sciences Index and Abstracts,CINAHLCumulative Index to Nursing and Allied Health Literature,IBSSInternational Bibliography of Social Sciences,PAIS InternationalPublic Affairs Information Service International