Funding for this research was provided by:
National Key Research and Development Program of China (2017YFD0400602)
Undergraduate Training Programs for Innovation and Entrepreneurship of Jiangsu province (201910312050Y, 201910312093T)
Priority Academic Program Development of Jiangsu Higher Education Institutions (Public Health and Preventive Medicine)
Received: 28 March 2020
Accepted: 9 July 2020
First Online: 14 July 2020
Ethics approval and consent to participate
: The present study was approved by the Nanjing Medical University Ethical Committee. Oral consent was obtained from the participants before conducting the study, and their written consent was obtained before the interview.
: Not applicable.
: The authors declare that they have no competing interests.