Funding for this research was provided by:
Japan Society for the Promotion of Science (JP19500579, JP23300246, JP15H03087, and 20K10473)
Received: 9 December 2020
Accepted: 9 February 2021
First Online: 17 February 2021
Ethics approval and consent to participate
: The study protocols were approved by the Ethics Committee of the University of the Ryukyus (No. 21, 139, 343). Study participants were provided information about the purpose and the ethical considerations of the study and an opportunity to decline to participate in the study at any time during the survey. The participants were also informed prior to administering the survey that returning the questionnaire constituted informed consent. The process of obtaining consent was approved by the ethics committee.
: Not applicable.
: The authors declare that they have no competing interests.