Funding for this research was provided by:
Guangxi Zhuang Region Health Department (Z2016506)
Received: 13 October 2020
Accepted: 13 January 2021
First Online: 21 January 2021
Ethics approval and consent to participate
: No ethical approval or patient consent was required because all the analyses were based on previously published studies.
: Not applicable.
: The authors declare that they no competing interest.