. 2021 Apr 30;100(17):e25596. doi: 10.1097/MD.0000000000025596
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.
Flow diagram of study selection process.