Received: 15 November 2020
Accepted: 18 February 2021
First Online: 5 March 2021
: This study was approved by the Medical Ethics Committee of Guizhou Medical University and undertaken with permission from the Health Information Center of Guizhou Provincial Health Commission. Participants were informed about the research, and gave informed consent prior to study participation. Respondents were participated on a voluntary basis.
: Not applicable.
: The authors declare that they have no competing interests.