Received: 26 September 2021
Accepted: 4 April 2022
First Online: 11 May 2022
: This study was conducted in accordance with ethical standards of the institutional research. committee. Data were de-identified and publicly available, and the Institutional Review Board approval was not applicable. The original CHARLS study was approved by the Biomedical Ethics Review Committee of Peking University. The ethical approval number was IRB00001052-11015. All patients provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interest.