Received: 4 March 2020
Accepted: 24 May 2020
First Online: 3 June 2020
Ethics approval and consent to participate
: The study protocol was approved by the medical ethics committee of Kushiro Red Cross Hospital (approval date: July 8, 2016). Written informed consent to participate in the study was obtained from all the patients.
: Not applicable.
: The authors declare that they have no competing interests.