Funding for this research was provided by:
Hallym University Research (HURF-2018-64)
Article History
Received: 21 March 2019
Accepted: 5 June 2019
First Online: 13 June 2019
Ethics approval and consent to participate
: This study adhered to the tenets of the Helsinki Declaration. Approval to perform research on human subjects in this study was provided by the Institutional Review Board of Korea University Medical Center Ansan Hospital (registration number: 2018AS0029). Due to the retrospective nature of this study, the usual requirement for signed written informed consent forms was waived.
: Not applicable.
: The authors declare that they have no competing interests.