. 2020 Aug 8;2020:7495161. doi: 10.1155/2020/7495161
Copyright © 2020 Hui-fang Li et al.
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Figure 2.
The risk of bias about each included study.