. 2014 Dec 2;93(28):e258. doi: 10.1097/MD.0000000000000258
© 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
This is an open access article distributed under the Creative Commons Attribution License 4.0, 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.
Studies evaluated for inclusion in this meta-analysis.