Received: 24 January 2022
Accepted: 27 April 2022
First Online: 6 May 2022
: This study was approved by the IRB of the Keio University School of Medicine (application number: 20200317) for conducting research with humans. The requirement for informed consent was waived because of the anonymous nature of the data used.
: Not applicable.
: The authors declare that they have no competing interests.