Funding for this research was provided by:
Health and Family Planning Commission of Hunan Province (A2017018)
Article History
Received: 7 December 2021
Accepted: 3 February 2022
First Online: 15 February 2022
Declarations
:
: The ethic review board of the National Center for Health Statistics approved all NHANES protocols.
: Not applicable.
: The authors declare that they have no competing interests.