Funding for this research was provided by:
National Research Foundation (No. 2017R1A2B2006435)
Text and Data Mining valid from 2020-01-10
Received: 27 July 2019
Accepted: 29 November 2019
First Online: 10 January 2020
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of Samsung Medical Center, which exempted the requirement for informed consent as we only used de-identified data retrieved from electronic medical records.<b>IRB</b> no. 2018–08–087-001<b>, Approval Date</b> 9/10/2018.
: Not applicable.
: The authors declare that they have no competing interests.