Text and Data Mining valid from 2018-09-03
Received: 18 November 2017
Accepted: 13 August 2018
First Online: 3 September 2018
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of Soonchunhyang University Seoul Hospital. (IRB number: 2014–11-029).
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.