Text and Data Mining valid from 2018-07-28
Received: 26 February 2018
Accepted: 24 July 2018
First Online: 28 July 2018
Ethics approval and consent to participate
: The study protocol was approved by the Konkuk Medical University Hospital Institutional Review Board (Approval number: KUH1010901), and the need for written informed consent from the participants was waived due to the retrospective nature of this study. It was conducted in accordance with the amended Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.
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