Funding for this research was provided by:
National Research Foundation of Korea (NRF-2020R1I1A1A01060447)
Received: 31 March 2021
Accepted: 9 June 2021
First Online: 26 June 2021
: The NHIS-HEALS data were fully anonymized for privacy protection. Due to the retrospective nature and use of de-identified data, the current study was approved with waiver of the requirement to obtain informed consent by the Institutional Review Board of the Yongin Severance Hospital (9–2020-0106). The study was performed in accordance with approved guidelines and regulations for medical research expressed in the Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.