Received: 31 March 2021
Accepted: 14 June 2021
First Online: 22 June 2021
: Verbal and written informed consents were obtained from all participants in this study, with participants having the right to quit the questionnaire at any time. All methods were carried out in accordance with relevant guidelines and regulations. The study protocol was approved by the ethics review committee of Sun Yat-sen University.
: Not applicable.
: The authors declare that they have no competing interests.