Text and Data Mining valid from 2020-05-07
Received: 31 January 2020
Accepted: 29 April 2020
First Online: 7 May 2020
Ethics approval and consent to participate
: This study was approved by the ethics committee of Ehime University Graduate School of Medicine (IRB No. 1507007). Informed consent was obtained from children’s caregivers.
: Not applicable.
: The authors declare that they have no competing interests.