Liu, Tingting
Ding, Silu
Dang, Jun http://orcid.org/0000-0002-1408-4749
Wang, Hui
Chen, Jun
Li, Guang
Article History
Received: 9 May 2019
Accepted: 30 September 2019
First Online: 16 October 2019
Ethics approval and consent to participate
: There was no ethics approval necessary because in this meta-analysis we were pulling numbers from the published manuscripts and pooling results.
: Not applicable.
: The authors declare that they have no competing interests.