Received: 10 June 2020
Accepted: 17 November 2020
First Online: 7 December 2020
Ethics approval and consent to participate
: This retrospective cohort study was conducted after approval from the Institutional Review Boards of Seoul National University Hospital (No. J-2004-002-1114) and Seoul National University Bundang Hospital (No. B-2004-607-103). This study was performed in accordance with the Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interest.