Zhang, Xiao-Ming
Zhang, Zhi-Biao
Chen, Wei
Wu, Xinjuan
Article History
Received: 16 September 2021
Accepted: 27 January 2022
First Online: 10 February 2022
Declarations
:
: All participants provided informed consent and this study was approved by the Health Statistics Research Ethics Review Board from the national center (protocol#2011–2017). All methods have followed the guidelines and regulations of the Declaration of Helsinki.
: Not applicable.
: There are no competing interests declared by the authors.