Funding for this research was provided by:
Beijing Hospitals Authority Talent Training Plan (QMS20191701)
Received: 8 August 2020
Accepted: 24 March 2021
First Online: 8 April 2021
Change Date: 24 April 2021
Change Type: Correction
Change Details: A Correction to this paper has been published:
Change Details: https://doi.org/10.1186/S12884-021-03823-4
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and with the 1964 Helsinki declaration and its later amendments. The study design was reviewed and approved by the Ethics Committee of Beijing YouAn Hospital, Capital Medical University (approval number: Jing-you-ke-lun-zi 050-hao). Permission to access and to use these data was approved by the institution. The need for informed consent was waived.
: Not applicable.
: The authors declare that they have no conflict of interest.