Funding for this research was provided by:
Ministry of Science and Technology of the People's Republic of China (2015FY111600)
Text and Data Mining valid from 2020-04-28
Received: 22 May 2019
Accepted: 8 April 2020
First Online: 28 April 2020
Ethics approval and consent to participate
: The medical ethics committee in Zhejiang university school of medicine approved this study. Each participant had signed informed consent before the face-to-face interview.
: Not applicable.
: The authors declare that they have no competing interests.