Text and Data Mining valid from 2020-04-29
Received: 3 April 2020
Accepted: 15 April 2020
First Online: 29 April 2020
Ethics approval and consent to participate
: This work was approved by the Institutional Review Board of Asan Medical Center (IRB number: S2018-1771-0001)
: All authors read and approved the final manuscript.
: The authors have no conflicts of interest to declare.