Funding for this research was provided by:
Korea Health Industry Development Institute (HI18C2383, HI18C1487)
Received: 12 October 2020
Accepted: 9 June 2021
First Online: 24 June 2021
: This study was approved by the institutional review board of Asan Medical Center and the need for written informed consent was waived considering the retrospective nature of the study.
: Not applicable.
: The authors declare that they have no conflict of interest.