Received: 27 May 2020
Accepted: 16 January 2021
First Online: 10 February 2021
Compliance with Ethical Standards
: Heewon Choi, Namki Hong, Narae Park, Chang Oh Kim, Hyeon Chang Kim, Jin Young Choi, Yoosik Youm, and Yumie Rhee have no conflicts of interest to declare.
: This study was approved by Institutional Review Board of Severance Hospital (IRB No. 4–2012-0172). All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and national research committees and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Written informed consent was obtained from all participants prior to the study.