Text and Data Mining valid from 2018-11-30
Received: 24 June 2018
Accepted: 19 November 2018
First Online: 30 November 2018
Ethics approval and consent to participate
: Data collection was approved by the Institutional Review Board of Chonbuk National University Hospital. Informed consent for this retrospective chart review was waived by the Institutional Review Board.
: 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.