. 2017 Mar 28;10:1875–1888. doi: 10.2147/OTT.S130147
© 2017 Han et al. This work is published and licensed by Dove Medical Press Limited
The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed.
Figure 1.
Flow diagram of publication search and study screening for the meta-analysis.