Funding for this research was provided by:
Scientific Research and Cultivation Program Foundation in Beijing China (No. PG2019018)
Text and Data Mining valid from 2020-02-10
Received: 27 March 2019
Accepted: 31 January 2020
First Online: 10 February 2020
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 the Hospital Infection Management Division and the director of the information center of Xuanwu Hospital at Capital Medical University grant permission to access the raw data of the study.
: Not applicable.
: The authors declare that they have no competing interests.