Funding for this research was provided by:
Japan Agency for Medical Research and Development/Japan International Cooperation Agency (jp18fk0108064)
Received: 13 April 2020
Accepted: 29 September 2020
First Online: 9 October 2020
Ethics approval and consent to participate
: Ethics approval was not applicable to this study based on Ethical Guidelines for Medical and Health Research Involving Human Subject issued by the Japanese Ministry of Health, Labour and Welfare since only completely encrypted data were used.
: Not applicable.