Funding for this research was provided by:
Department of Internal Medicine, Gangnam Severance Hospital (2019-GNS-001)
Received: 21 April 2020
Accepted: 24 July 2020
First Online: 31 July 2020
Ethics approval and consent to participate
: This study was approved by the institutional review board (IRB) of Gangnam Severance Hospital (IRB No. 3-2019-0423). Owing to the retrospective nature of this study, the requirement for informed consent was waived.
: Not applicable.