Sun, Ani
Gao, Wenni
Xiao, Ting
Article History
Received: 19 November 2019
Revised: 11 February 2020
Accepted: 28 February 2020
First Online: 5 March 2020
Ethics approval and consent to participate
: Ethical approval and consent to participate were not necessary because this study was a meta-analysis.
: Not applicable.
: The authors declare that they have no competing interests.