Received: 1 October 2021
Accepted: 31 December 2021
First Online: 17 February 2022
: Ethical approval was granted by the Ethics Committee for Epidemiological Research at Hiroshima University (Ref. no. E-1389). The study was conducted according to the Declaration of Helsinki. The need to obtain informed consent from each subject was waived as this was a retrospective review of the subjects’ records according to the Ethical Guidelines for Medical and Health Research Involving Human Subjects in Japan. The name of the ethics committee that waived the requirement of informed consent was the Ethics Committee for Epidemiological Research at Hiroshima University.
: Not applicable.
: The authors declare that they have no competing interests.