Received: 25 April 2020
Accepted: 25 June 2020
First Online: 6 July 2020
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of Wuhan Central Hospital. As it was a retrospective study and did not require protection of patients’ privacy, we were exempted from obtaining informed consent.
: Not applicable.
: The authors declare that they have no competing interests.