Funding for this research was provided by:
The First Hospital of Qiqihar City (R073290127)
U.S. Department of Veterans Affairs (I01 BX000671)
Received: 3 March 2020
Accepted: 2 June 2020
First Online: 17 June 2020
Ethics approval and consent to participate
: This retrospective analysis was approved by the Institutional Review Board.
: Not applicable.
: The authors declare that they have no competing interests.