Received: 4 January 2019
Accepted: 7 May 2019
First Online: 16 May 2019
Compliance with ethical standards
: Shizuka Shimabukuro has received speaker fees from Shire. Other authors report no potential conflicts of interest.
: Ethical approval for the study was obtained from the Okinawa Institute of Science and Technology Graduate University Human Subjects Research Review Committee. Participating parents, teachers, and children were volunteers and provided written informed consent.
: Not applicable.