Funding for this research was provided by:
Ministry of Health, Labour and Welfare (21AA2007, 20AA2005)
Ministry of Education, Culture, Sports, Science and Technology (20H03907)
Received: 30 October 2021
Accepted: 10 December 2021
First Online: 20 December 2021
: The Institutional Review Board of The University of Tokyo approved this study. The procedures used in this study adhere to the tenets of the Declaration of Helsinki. No information allowing the identification of individual patients, hospitals, or physicians was obtained, and the requirement for informed consent was waived because of the anonymous nature of the data.
: Not applicable.
: The authors declare that they have no competing interests.