Article History
Received: 15 July 2019
Accepted: 9 September 2019
First Online: 26 October 2019
Compliance with ethical standards
:
: Korea National Health and Nutrition Examination Survey (KNHANES) adheres to the principles outlined in the Declaration of Helsinki for research involving humans; all participants provided written informed consents and the protocol for KNHANES was approved by the Institutional Review Board of Korea Center for Disease Control and Prevention (No. 2008-04EXP-01-C, 2009-01CON-03-2C, 2010-02CON-21-C, and 2011-02CON-06-C). The current study did not require additional approval because the KNHANES dataset is publicly available (ExternalRef removed).
: Informed consent was not required for this study because anonymized and de-identified data was used for the analyses.
: None.