Funding for this research was provided by:
Seoul National University Hospital (no 14-2014-023)
Text and Data Mining valid from 2018-10-22
Received: 17 July 2018
Revised: 27 August 2018
Accepted: 19 September 2018
First Online: 22 October 2018
Compliance with ethical standards
: The scientific guarantor of this publication is Chang Jin Yoon.
: The authors declare that they have no conflict of interest.
: No complex statistical methods were necessary for this paper.
: Written informed consent was waived by the Institutional Review Board.
: Institutional Review Board approval was obtained.
: • Retrospective• Experimental study• Performed at one institution