Received: 31 October 2019
Accepted: 26 March 2020
First Online: 18 April 2020
Compliance with Ethical Standards
: The protocol for this research project has been approved by constituted Ethics Committee of the Kawasaki Medical School and Saitama Medical University International Medical Center. It conforms to the provisions of the Declaration of Helsinki in 1995.
: The authors declare that they have no conflicts of interest.