Funding for this research was provided by:
Scientific Research and Cultivation Program Foundation in Beijing China (PG2019018)
Received: 19 April 2019
Accepted: 10 July 2019
First Online: 19 July 2019
Ethics approval and consent to participate
: The study design was approved by the ethics review board of Xuanwu Hospital, Capital Medical University. The director of Hospital Infection Management Division and the director of information center of Xuanwu Hospital, Capital Medical University, grant permission for access the raw data of the study.
: Not applicable.
: The authors declare that they have no competing interests.