Received: 20 January 2020
Accepted: 9 May 2020
First Online: 28 May 2020
Ethics approval and consent to participate
: The study was approved by the Clinical Research Institute of Seoul National University Bundang Hospital (approved on March 11 2019; IRB No. B-1903-531-105). Because of the retrospective study design without randomization or intervention, the requirement of informed consent for each individual was waived by the institutional review board.
: Goo-Yeong Cho, the corresponding author, confirms that this study has been reported honestly, accurately, and transparently. All authors read and approved the final manuscript.
: The authors declare that they have no competing interests.