Document is current

Article History

Received: 8 January 2018

Accepted: 27 November 2018

First Online: 10 December 2018

Ethics approval and consent to participate

: The study protocol was approved by the Institutional Review Board of Konkuk University Medical Center and Asan Medical Center and was conducted in accordance with the amended Declaration of Helsinki. All participants provided written informed consent before enrollment.

: Not applicable

: The authors declare that they have no competing interests.

: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.