Received: 28 April 2021
Accepted: 15 October 2021
First Online: 8 December 2021
: Ethical approval was obtained from the Ethics and Research Committee of the First Hospital of Lanzhou University, Lanzhou, Gansu, China. (Serial number: LDYYLL 2019–20); In our survey all methods were carried out in accordance with relevant guidelines and regulations. Also informed consent has been obtained from all participants and from legally authorized representative of illiterate participant sprior to the interview. Before the survey, the staff must explain to the respondents the purpose, significance and process of the survey.
: Not applicable.
: The authors declared no conflict of interest.