Li, Yong
Article History
Received: 12 January 2023
Accepted: 25 July 2023
First Online: 23 August 2023
Declarations
:
: The CHARLS surveys were approved by the Ethical Review Committee of Peking University. All participants provided written informed consent. Study was carried out in accordance with ethical guidelines of Peking University. This study was approved by the Ethics Committee of Beijing Anzhen Hospital Capital Medical University (2022238). All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The study was not conducted with animals.
: Not applicable .
: The author declares that there are no conflicts of interest.