Funding for this research was provided by:
Supported by 1.3.5 project for disciplines of excellence, West China Hospital, Sichuan University (ZY2017201)
Received: 23 October 2020
Accepted: 27 April 2021
First Online: 8 May 2021
: This study was approved by the Ethics Committee of West China Hospital, Sichuan University. Participants were recruited by advertising and asked verbally by the researchers about their willingness to take part in the study. Before investigation, informed consent was signed and obtained by each participant(the participants who were unable to write issued an authorization letter to their legal guardians by providing a thumb print and the authorization letter were also signed by the legal guardians. After being authorized, the legal guardians proceeded to provide written consent on behalf of the participants and the participants then assented by providing a thumb print).
: Not applicable.
: The authors declare no competing interests.