Funding for this research was provided by:
the start-up funds for talent introduction in the Second Affiliated Hospital of Hainan Medical University (KYQDJ-2019-02)
Text and Data Mining valid from 2020-04-22
Received: 16 December 2019
Accepted: 13 April 2020
First Online: 22 April 2020
Ethics approval and consent to participate
: The Hainan Medical University Clinic Institutional Review board approved this study, and the need for patient consent was waived due to the retrospective study design.
: Not applicable.
: The authors declare that they have no competing interests.