Funding for this research was provided by:
Health and Labour Science Research Grants
Text and Data Mining valid from 2018-04-05
Received: 26 December 2017
Accepted: 20 March 2018
First Online: 5 April 2018
Ethics approval and consent to participate
: Written informed consent was obtained from each participant before registration at each institution. The local ethics committee of each institute approved this study, namely, the ethics committees of Shiga University of Medical Science, Tokyo Medical and Dental University, Keio University, National Hospital Organization Okayama Medical Center, University of Toyama, Kitasato Institute Hospital, National Hospital Organization Murayama Medical Center, Hirosaki University Graduate School of Medicine, Chiba University Graduate School of Medicine, Hamamatsu University School of Medicine, Jichi Medical University, Kagoshima University, University of Yamanashi, Tokai University School of Medicine, Niigata University Medicine and Dental General Hospital, Tohoku Medical and Pharmaceutical University Tohoku University School of Medicine, Nagoya University Graduate School of Medicine, Kyoto University, and University of Tsukuba.
: Not applicable.
: The authors declare that they have no competing interests.
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