Funding for this research was provided by:
Innovation and Technology Fund of Zhongnan Hospital, Wuhan University (cxpy20160027)
Received: 15 October 2018
Accepted: 24 December 2019
First Online: 8 January 2020
Ethics approval and consent to participate
: The study was approved by the ethics committee of the Zhongnan Hospital, Wuhan University. The requirement for informed consent was waived by the ethics committee of Zhongnan hospital given the retrospective design. And data used in this study was anonymised before its use.
: Not applicable.
: The authors declare that they have no competing interests.