Received: 1 June 2020
Accepted: 23 August 2020
First Online: 27 August 2020
Ethics approval and consent to participate
: This study was conducted in accordance with the ethical principles of the Declaration of Helsinki and with the Ethical Guidelines for Epidemiological Research issued by the Ministry of Health, Labour, and Welfare of Japan. The study was approved by the Ethics Review Committee of Jikei University School of Medicine (ID: 9573). As the data were obtained retrospectively from patient charts, informed consent was deemed unnecessary following the above guidelines.
: Not applicable.
: The authors declare no competing financial interests.