Received: 1 June 2017
Accepted: 12 January 2018
First Online: 14 February 2018
Ethics approval and consent to participate
: The study was approved by the Ethical Committee of Tokushukai Group Institutional Review Board (approval number IRB no. TGE00532-024) and was conducted under the Declaration of Helsinki. This report adopted an opt-out consent instead of the written informed consent. We provided patients with information explaining the proposed research project (the purpose, required individual data, and duration of research) by means of an information sheet or a website of the hospital, and gave them the opportunity of opt-out.
: Not applicable.
: The authors declare that they have no competing interests.
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