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Article History

Received: 20 January 2018

Accepted: 26 November 2018

First Online: 11 December 2018

Ethics approval and consent to participate

: This study protocol was approved by the ethics committee of the Okayama University (approval number: 1032) and conducted in accordance with the Declaration of Helsinki. Considering the longitudinal nature of the study and large number of participants, verbal or written consent was not obtained from all participants. The study was advertised on posters in medical examination centers for a certain period of time. Patients were asked to participate either through the website or in person. Their participation in the survey was taken as consent to participate. This protocol was approved by the ethics committee. The data were analyzed anonymously.

: Not applicable.

: The authors declare that they have no competing interests.

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