Funding for this research was provided by:
National Research Foundation of Korea (NRF-2020-R1G1A1005390)
Received: 4 August 2020
Accepted: 8 February 2021
First Online: 27 February 2021
Ethics approval and consent to participate
: The study was performed in accordance with ethical standard of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The study was approved by the ethics committee of Seoul National University Bundang Hospital (No. B-2008-630-005). The requirement for written informed consent was waived by the Institutional Review Board due to retrospective chart review.
: Not applicable.
: The authors declare no conflict of interest.