. 2016 Dec 9;95(49):e5540. doi: 10.1097/MD.0000000000005540
Copyright © 2016 the Author(s). Published by Wolters Kluwer Health, Inc. All rights reserved.
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 the study selection process.