Received: 25 October 2021
Accepted: 31 March 2022
First Online: 11 April 2022
: The KNHANES was approved by the Institutional Review Board of Korea Centers for Disease Control and Prevention (IRB No: 2008-04EXP-01-C, 2009-01CON-03-2C, 2010-02CON-21-C and 2011-02CON-06-C) and the requirement for informed consent was waived because anonymous and de-identified information was used. Our study adhered to the principles of the Declaration of Helsinki.
: Not applicable.
: The authors have no conflicts of interest to disclose relevant to this article.