. 2019 Jan 15;7(1):e12297. doi: 10.2196/12297
©Xinghan Wu, Xitong Guo, Zhiwei Zhang. Originally published in JMIR Mhealth and Uhealth (http://mhealth.jmir.org), 15.01.2019.
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Figure 2.
Risk of bias in each study. Green: low risk of bias; yellow: unclear risk of bias; red: high risk of bias.