Lu, Jiao
Liu, Linhui
Zheng, Jiaming
Zhou, Zhongliang
Article History
Received: 19 August 2021
Accepted: 11 March 2022
First Online: 13 April 2022
Declarations
:
: The study used secondary data from CHARLS which are publicly available. The original CHARLS was approved by the Ethical Review Committee of Peking University, and all participants signed informed consent forms. We determined that all methods comply with institutional or national research Council ethical standards, and the Helsinki Declaration of 1964 and its subsequent amendments or similar ethical standards.
: Not applicable.
: All authors declare no competing interests.