Ethics approval and consent to participate
Ethics approval was obtained from the Institutional Review Boards of Hokkaido University Hospital and Tokyo Medical University (study approval no. 013–0184 and SH3308, respectively).
Consent for publication
Written informed consent was obtained from all participants prior to their enrollment in the study.
Availability of data and materials
Detailed data are available from the corresponding authors upon reasonable request.
Competing interests
Yota Fujimura has received honoraria from Sumitomo Pharma, and has research and grant support from Otsuka Pharmaceutical, Sumitomo Pharma, and Shionogi. Akiyoshi Shimura has received lecture fee from Sumitomo Pharma and Eisai. Yu Tamada has received honoraria from Otsuka Pharmaceutical, Sumitomo Pharma, Eisai, MSD and Meiji Seika Pharma.Ichiro Kusumi has received honoraria from Eisai, Eli Lilly, Janssen Pharmaceutical, Meiji Seika Pharma, Mochida Pharmaceutical, Novartis Pharma, Otsuka Pharmaceutical, Shionogi, Sumitomo Pharma, Takeda Pharmaceutical, Viatris, and Yoshitomiyakuhin, and has received research/grant support from Asahi Kasei Pharma, Astellas, Daiichi Sankyo, Eisai, Eli Lilly, Mochida Pharmaceutical, Nihon Medi-Physics, Otsuka Pharmaceutical, Pfizer, Shionogi, Sumitomo Pharma, Takeda Pharmaceutical and Tanabe Mitsubishi Pharma.
Takeshi Inoue is a member of the advisory boards of Pfizer, Novartis Pharma, and Mitsubishi Tanabe Pharma, and has received personal fees from Mochida Pharmaceutical, Takeda Pharmaceutical, Eli Lilly, Janssen Pharmaceutical, MSD, Taisho Toyama Pharmaceutical, Yoshitomiyakuhin, and Daiichi Sankyo; grants from Shionogi, Astellas, Tsumura, and Eisai; and grants and personal fees from Otsuka Pharmaceutical, Dainippon Sumitomo Pharma, Mitsubishi Tanabe Pharma, Kyowa Pharmaceutical Industry, Pfizer, Novartis Pharma, and Meiji Seika Pharma. The other authors declare that they have no actual or potential conflicts of interest associated with this study.
Funding
This work was partly supported by a Grant-in-Aid for Scientific Research (no. 16 K10194 to TI) from the Japanese Ministry of Education, Culture, Sports, Science and Technology, Research and Development Grant for Comprehensive Research for Persons with Disabilities from Japan Agency for Medical Research and Development (AMED), and a grant from SENSHIN Medical Research Foundation.
Authors’ contributions
YF and TI designed the study, wrote the protocol, and collected and analyzed the data. All authors contributed to data analysis, drafting and critically revising the paper, gave final approval of the version to be published, and agreed to be accountable for all aspects of the work.
Acknowledgements
We thank Dr. Yukiei Nakai and Dr. Mayu Naruse for collecting data and editing the manuscript. We thank Dr. Helena Popiel of the Center of International Education and Research, Tokyo Medical University, for editorial review of the manuscript.