Funding for this research was provided by:
Received: 25 October 2017
Accepted: 15 May 2018
First Online: 24 May 2018
Ethics approval and consent to participate
: This was an observational study using de-identified medical claims data. Because the Japanese Ethical Guidelines for Medical and Health Research Involving Human Subjects (ExternalRef removed) do not apply to studies exclusively using de-identified data, we were not obligated to apply for an ethical approval for this study and to obtain informed consent in this study.
: DJR, JT, and GF are employed by MSD K.K. TK has no competing interests to declare on this work.
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