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Article History

Received: 16 June 2017

Accepted: 22 November 2018

First Online: 3 December 2018

Ethics approval and consent to participate

: Ethics approval was obtained from the Clinical Research Review Committee, Asan Medical Center (#2012–0820), Seoul, Korea. Written consent regarding voluntary participation was obtained from each participant after full explanation of the study.

: Participants consented to publication of the data without specific identifying data.

: The authors declare that they have no competing interests.

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