Received: 13 September 2020
Accepted: 1 February 2021
First Online: 18 February 2021
Ethics approval and consent to participate
: The study protocol was approved by the ethics committee of Chiba University Graduate School of Medicine and the ethics committee of the International University of Health and Welfare before implementation. Participants were informed that their participation was voluntary. Participants were rewarded according to the regulations of Cross Marketing Group Inc.
: We did not gather any personally identifiable information about participants.
: The authors declare that they have no competing interests regarding this study.