Received: 3 March 2020
Accepted: 30 April 2020
First Online: 18 May 2020
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of Gyeongsang National University Hospital and conducted in accordance with the Good Clinical Practice guidelines and the Declaration of Helsinki. Informed consent was waived because of the retrospective nature of the study.
: Not applicable.
: The authors declare that they have no competing interests.