Funding for this research was provided by:
Postdoctoral Research Foundation of China (2019M653685)
Shaanxi Social Science Foundation (2019S038)
National Natural Science Foundation of China (72004180, 71874137)
Received: 12 July 2020
Accepted: 9 December 2020
First Online: 6 January 2021
Ethics approval and consent to participate
: Informed consent was obtained from household members before the interview. Approval for this study was obtained by the Ethics Committee of Health Science Center, Xi’an Jiaotong University (approval number 2020–1256).
: Not applicable.
: The authors declare that they have no competing interests.