Funding for this research was provided by:
Ministry of Education, Culture, Sports, Science and Technology (JP16H06395)
Text and Data Mining valid from 2020-02-11
Received: 8 August 2019
Accepted: 29 January 2020
First Online: 11 February 2020
Ethics approval and consent to participate
: We obtained online informed consent from all participants, by asking the participants to read terms and conditions and to press “agree”. The study protocol was approved by the research ethics committee of the Graduate School of Medicine and the Faculty of Medicine, The University of Tokyo, Japan.
: Not applicable.
: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential competing interests.