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. 2018 May 5;8(5):e019101. doi: 10.1136/bmjopen-2017-019101

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PRISMA flow diagram (from Moher et al ⁸⁸). CINAHL, Cumulative Index to Nursing and Allied Health Literature; EMRO, Eastern Mediterranean Regional Office; RCT, randomised controlled trial. *Articles may be duplicated between the excluded groups.