. 2021 May 21;100(20):e25534. doi: 10.1097/MD.0000000000025534
Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.
This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. http://creativecommons.org/licenses/by/4.0
Figure 1.
The flow diagram of the study selection process.