Funding for this research was provided by:
National Research Foundation of Korea (2017R1C1B5076977)
Received: 26 June 2020
Accepted: 2 October 2020
First Online: 13 October 2020
Ethics approval and consent to participate
: This retrospective cohort study was approved by the institutional review board (IRB No. 2019-10-039-001), and the need for written informed consent was waived.
: Not applicable.
: All authors have no competing interests for this paper.