Funding for this research was provided by:
Scientific Research Fund Project of Hebei Provincial Health and Family Planning Commission (20180691)
Article History
Received: 7 October 2020
Accepted: 8 February 2021
First Online: 9 March 2021
Ethics approval and consent to participate
: The study was approved by the Ethics Committee of General Hospital of Cangzhou Central Hospital (2018066). All patients provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.