Received: 11 December 2019
Accepted: 10 May 2020
First Online: 28 May 2020
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of the Gangnam Severance Hospital, Yonsei University College of Medicine, with the waiver of the informed consent as well as the relevant permission forms have been obtained from the NHI Sharing Service.
: Not applicable.
: The authors declare that they have no competing interests.