Funding for this research was provided by:
Department of Health of Hebei Province (20200042)
Received: 16 June 2020
Accepted: 28 September 2020
First Online: 8 October 2020
Ethics approval and consent to participate
: This study has been reviewed by the Ethics Committee of the second hospital of Hebei Medical University (number 2020-R127), all procedures performed in studies involving human participants were conducted according to the ethical standards of the institutional research committee and the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Not applicable.
: The authors declare that they have no competing interests.