Funding for this research was provided by:
Research on Global Health Issues (H24-chikyukibo-ippan-004)
Received: 24 July 2020
Accepted: 21 December 2020
First Online: 22 January 2021
Ethics approval and consent to participate
: The study protocol was reviewed and approved by the Osaka University Research Committee (approval number: 12145), the Nagoya University School of Medicine Bioethics Review Committee (approval number: 2012-0103), and the Institutional Review Board of the Ministry of Health, Republic of Palau. Written informed consent was obtained from all of the participants prior to the study.
: Not applicable.
: The authors declare that they have no competing interests.