Funding for this research was provided by:
Yonsei University College of Medicine (6-2017-0149)
Received: 15 April 2019
Accepted: 12 June 2020
First Online: 19 June 2020
Ethics approval and consent to participate
: All procedures performed in this study were in accordance with the ethical standards of the institutional and national research committee and the 1964 Helsinki Declaration and its later amendments. Approval for this study was obtained from the Gangnam Severance Hospital Institutional Review Board for the retrospective review of existing patient records (IRB number: 3–2017-0193). Requirement for patient consent was waived by the institutional review board because of the retrospective study design and data anonymization.
: Not applicable.
: The authors declare that they have no competing interests.