Funding for this research was provided by:
National Research Foundation of Korea (NRF-2017R1A2B2011520)
Text and Data Mining valid from 2019-12-01
Received: 29 July 2019
Accepted: 7 November 2019
First Online: 11 December 2019
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of Gangnam Severance Hospital, Yonsei University College of Medicine (IRB No. 3-2019-0005).
: Not applicable.
: The authors declare that they have no competing interests.