. 2016 Dec 23;95(51):e5692. doi: 10.1097/MD.0000000000005692
Copyright © 2016 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 2.
Risk of bias summary.