Xie, Yaofei
Ma, Mengdi
Wang, Wei
Article History
Received: 29 August 2022
Accepted: 17 May 2023
First Online: 16 June 2023
Declarations
:
: The authors declare no competing interests.
: The CHARLS project was approved by Biomedical Ethics Committee of Peking University. All the participants signed the informed consent form before the investigations. The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008.
: Not applicable.