Article History
Received: 7 July 2017
Accepted: 12 April 2018
First Online: 17 April 2018
Ethics approval and consent to participate
: This study was approved by the Medical Ethical Committee of National Hospital Organization Tochigi Medical Center (No. 28-20). This study was conducted in accordance with the Ethical Guidelines for Epidemiological Research in Japan. The need for individual informed consent was formally waived by the Medical Ethical Committee of National Hospital Organization Tochigi Medical Center because the data were collected from medical records and the patients were not contacted. However, according to Japanese Ethical Guidelines, we did display a poster in the waiting room of the hospital to provide information about the collection and use of data for this study and the protection of personal information.
: The authors declare that they have no competing interests.
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