Funding for this research was provided by:
Grants-in-Aid for Scientific Research, Japan (KAKENHI-15H05685)
Received: 10 May 2019
Accepted: 21 August 2019
First Online: 5 September 2019
Ethics approval and consent to participate
: The ethics committee of the Nippon Medical School Tama Nagayama Hospital approved the present study. Our analysis did not include personal identifying information, so the requirement for written informed consent was waived.
: Not applicable.
: The authors declare that they have no competing interests.