Funding for this research was provided by:
Ministry of Education, Culture, Sports, Science and Technology (JP18K17979)
Text and Data Mining valid from 2018-11-24
Received: 12 September 2018
Accepted: 8 November 2018
First Online: 24 November 2018
Ethics approval and consent to participate
: The present study was approved by the medical ethics committee of Showa University School of Medicine (Approval No. 2407) and the Ethics Committee of the All Japan Labor Welfare Foundation (Approval No. 9-1-0007). Informed consent for the use of personal information in this study was obtained from each participant.
: Not applicable.
: The authors declare that they have no competing interests.
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