Received: 31 January 2020
Accepted: 28 July 2020
First Online: 7 August 2020
Ethics approval and consent to participate
: For this retrospective study, written informed consent from the participants was unavailable and unnecessary. The Ethical Committee of Jikei University School of Medicine stated that patient consent was not necessary for this retrospective study. We performed opt-out consent on the website of our hospital. This study was approved by the Ethical Committee [30–319 (9340)].The director/administer of Jikei University Hospital granted us permission to access the medical records. The data used in this study was anonymized before its use.
: Not applicable.
: The authors declare that they have no competing interests.