Yu, Jintao
Guo, Jiawen
Zhang, Hengguo
Cheng, Xu
Article History
Received: 17 December 2021
Accepted: 28 March 2022
First Online: 2 April 2022
Declarations
:
: All participants provided written informed consent, and the protocol was approved by the Research Ethics Review Board of National Center for Health Statistics.
: The authors declare no competing interests.