Funding for this research was provided by:
National Research Foundation of Korea (MRC2014009392, 2014M3C7A1064752, MRC2014009392, 2014M3C7A1064752)
Received: 26 September 2020
Accepted: 29 December 2020
First Online: 12 January 2021
Ethics approval and consent to participate
: Ethical approval was given by the Institutional Review Board of each center (INHAUH 2015-03-021). All participants or their legal representatives voluntarily agreed to participate and provided written informed consent.
: Not applicable.
: The authors have no disclosure for any conflicts of interest, including financial interests, relationships, activities, and affiliations.