Funding for this research was provided by:
National Institute of Arthritis and Musculoskeletal and Skin Diseases (U19 AR069519)
Text and Data Mining valid from 2019-08-10
Accepted: 3 August 2019
First Online: 10 August 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
: All participating parents provided informed consent. Participating children ages 14–17 years also gave informed consent, while children ages 8–13 years provided assent.