Funding for this research was provided by:
Korea University grant (K2011221)
Article History
Received: 2 October 2020
Revised: 5 December 2020
Accepted: 11 December 2020
First Online: 8 January 2021
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: This study was performed in line with the principles of the Declaration of Helsinki and approved by the Institutional Review Board of the Korea University Hospital, Seoul, Korea (IRB number: 2020AN0159), and adhered to the tenets of the Declaration of Helsinki.
: This retrospective study involves no more than minimal risk to subjects, and the IRB of the Korea University Hospital approved our request to waive the informed consent.
: Not applicable.
: Not applicable.