Received: 10 February 2021
Accepted: 17 May 2021
First Online: 9 June 2021
: This study was approved by the clinical research ethics committee of Seoul National University College of Medicine and Hospital (IRB No. 2007–152-1143). All methods were performed in accordance with relevant guidelines and regulations. Informed consent was obtained from all participants, by clicking on the “start” button on the front page of the online survey. The survey was anonymous, and confidentiality of information was assured.
: Not applicable.
: The authors declare that they have no competing interests.