Text and Data Mining valid from 2019-11-04
Received: 10 October 2018
Accepted: 15 October 2019
First Online: 4 November 2019
Ethics approval and consent to participate
: This study was approved by the Seoul National University Bundang Hospital institutional review board (IRB No: B-1507/306–104). Requirement for informed consent was waived and data collection was conducted under accordance with World Medical Association’s Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interest.