. 2020 Aug 4;8(8):e15779. doi: 10.2196/15779
©Kaifeng Liu, Zhenzhen Xie, Calvin Kalun Or. Originally published in JMIR mHealth and uHealth (http://mhealth.jmir.org), 04.08.2020.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR mHealth and uHealth, is properly cited. The complete bibliographic information, a link to the original publication on http://mhealth.jmir.org/, as well as this copyright and license information must be included.
Figure 2.
Risk of bias of the 27 trials.