Funding for this research was provided by:
Ministry of Education (2019R1C1C1006417)
Received: 18 September 2019
Accepted: 15 September 2021
First Online: 23 September 2021
: This study was approved by the Institutional Review Board of Chung-Ang University Hospital (No. C2014211) and the written informed consent was waived because of the non-interventional retrospective nature of this study. Written permissions to access the raw data of this study were obtained from hospital authorities. The data was anonymized before its use. The implementation of all stages of the study has been conducted in accordance with the ethical standards and the tenets of the Declaration of Helsinki.
: Not applicable.
: The authors declare no competing interests.