Received: 14 October 2020
Revised: 25 November 2020
Accepted: 1 December 2020
First Online: 7 December 2020
Ethics approval and consent to participate
: Approval for this retrospective observational study (approval no. 567) was provided by the Ethical Committee of Kumamoto City Hospital, Kumamoto, Japan, on October 8, 2020.
: All data were pre-existing data obtained from the patient’s medical records and did not include any personal information that would identify any of the patients. Informed consent from the patients was therefore waived, based on the Ethical Guidelines for Epidemiological Studies issued by the Ministry of Health, Labour and Welfare and Ministry of Education, Culture, Sports, Science, and Technology of Japan.
: The author declares that he has no competing interests.