. 2017 Apr 26;19(4):e132. doi: 10.2196/jmir.6641
©Cheng K Fred Wen, Stefan Schneider, Arthur A Stone, Donna Spruijt-Metz. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 26.04.2017.
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Figure 2.
The preferred reporting items for systemic review and meta-analysis (PRISMA) diagram.