Received: 3 October 2018
Accepted: 20 September 2019
First Online: 6 November 2019
Ethics approval and consent to participate
: The NHANES survey operates under the approval of the National Center for Health Statistics Research Ethics Review Board (Protocols #2005-06, and #2011-17), available in ExternalRef removed. All the NHANES data meet the conditions described in Research Using Publicly Available Datasets (Secondary Analysis) - Policy #39 - for use without application to Institutional Review Board. All study participants provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.