Funding for this research was provided by:
National Research Foundation of Korea (2019R1A2C1004966)
Received: 3 September 2020
Accepted: 5 May 2021
First Online: 24 May 2021
: The 2011–2014 NHANES was approved by the US National Center for Healthcare Statistics (NCHS) Research Ethics Review Board (ERB) (protocol number: protocol#2011-17 and continuation of protocol #2011-17) (ExternalRef removed). This study was exempt from formal ethics review as a secondary analysis of existing NHANES public data under the US Health & Human Services regulations at 45 CFR 46.101(b) (ExternalRef removed).
: Not applicable.
: The authors declare that they have no competing interests.