Li, Wenjuan
Li, Jie
Fu, Peipei
Chen, Yan
Yuan, Yemin
Yang, Shijun
Li, Jie
Li, Zhixian
Yan, Chen
Gui, Zhen
Zhou, Chengchao
Article History
Received: 29 January 2021
Accepted: 11 May 2021
First Online: 30 June 2021
Declarations
:
: The Ethical Committee of Shandong University School of Public Health reviewed and approved the study protocol. All participants gave their informed written consent for participation prior to the face-to-face interview. All procedures performed in this study involving human participants were in accordance with the Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.