Funding for this research was provided by:
The 13th Five-year-planned Project of Philosophy and Social Sciences Development of Guangzhou, Guangdong Province, China (grant no. 2018GZYB133)
The National Social Science Fund of China (grant no. 18BRK034)
Received: 2 January 2021
Accepted: 7 March 2021
First Online: 25 March 2021
: Ethical approval was sought from the Ethics Committee of Guangzhou Medical University (L180920). Participants provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.