Funding for this research was provided by:
National Center for Complementary and Integrative Health (R00AT009156)
Received: 12 December 2018
Accepted: 24 June 2019
First Online: 9 July 2019
Ethics approval and consent to participate
: NHANES study protocol have been reviewed and approved by the National Center for Health Statistics institutional review board and written informed consents were obtained from all participants.
: Not applicable.
: The author declares that he/she has no competing interests.