Funding for this research was provided by:
National Health Insurance Service Ilsan Hospital (NHIMC2018CR043)
Received: 30 August 2019
Accepted: 26 March 2020
First Online: 18 April 2020
Ethics approval and consent to participate
: This retrospective study was approved by the Institutional Review Board of Severance Hospital (4–2015-0954) and National Health Insurance Service Ilsan Hospital (NHIMC 2018–04-021). Informed consent was waived owing to the retrospective nature of this study.
: Not applicable.
: The authors declare that they have no competing interests.