Received: 19 November 2019
Accepted: 16 June 2020
First Online: 29 June 2020
Ethics approval and consent to participate
: This study was approved by the Peking Union Medical College Hospital ethics committee (approval number JZ1759). All subjects were informed of the details regarding the design and aims of the research study, and written informed consent was obtained from all patients for the use of their data in these studies.
: Not applicable.
: The authors declare that they have no competing interests.