Funding for this research was provided by:
Japan Society for the Promotion of Science (JP20K08015, JP17H01744, JP20K19857)
Hokkaido University (Grants-in-Aid for Cross-departmental Young Researcher Grants)
Received: 14 October 2020
Accepted: 11 January 2021
First Online: 25 January 2021
Ethics approval and consent to participate
: The ethics committees of the institutions (The Ethics Review Board of Hyogo College of Medicine, and The Ethics Committee at Hokkaido University Faculty of Medicine) provide approval for this study. The requirement for patients' informed consent was waived in light of the retrospective nature of the study.
: The requirement for patients' consent for publication was waived in light of the retrospective nature of the study.
: The authors declare that they have no competing interests.