Funding for this research was provided by:
Ministry of Health, Labour and Welfare (H27-policy-strategy-013, H29-policy-strategy-005)
The Institute for Health Economics and Policy (Grant for Young Researcher B, H28)
Text and Data Mining valid from 2019-11-23
Received: 8 May 2019
Accepted: 23 September 2019
First Online: 23 November 2019
Ethics approval and consent to participate
: This study complies with the “Ethical guidelines for epidemiological research” of the Ministry of Health, Labor and Welfare of Japan. This study has been reviewed and approved by a Ministry of Health, Labor and Welfare panel of experts and approved by the Kyoto University medical ethics committee (reference number: R0635).We used unlinkable anonymized data, and individuals cannot be identified.The data obtained in this study were not used for purposes other than this study and data sharing not applicable. This study is an observational study using existing data, and matters of advantage or disadvantage to research participants, or that cause new invasion or adverse events to research participants, do not apply.
: This study used unlinkable anonymized data, and individuals cannot be identified.
: The authors declare that they have no competing interests. Declarations of COI from each researcher are managed by Kyoto University and Kyoto University Hospital.