Article History
Received: 20 August 2018
Revised: 23 October 2018
Accepted: 14 November 2018
First Online: 14 December 2018
Compliance with ethical standards
:
: The scientific guarantor of this publication is Myeong-Jin Kim.
: The authors of this manuscript declare no relationships with any companies, whose products or services may be related to the subject matter of the article.
: 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• case-control study• performed at one institution