Funding for this research was provided by:
National Natural Science Foundation of China (81800667)
1.3.5 project for disciplines of excellence, West China Hospital, Sichuan University (ZY2016104)
Project of Sichuan Provincial Health Department (ZH2017-101)
Received: 29 October 2018
Accepted: 28 May 2019
First Online: 7 June 2019
Ethics approval and consent to participate
: All analyses were based on previous published studies. Thus, no ethical approval and patient consent are required.
: Not applicable.
: The authors declare that they have no competing interests.