Text and Data Mining valid from 2019-01-14
Received: 11 August 2018
Accepted: 7 January 2019
First Online: 14 January 2019
Ethics approval and consent to participate
: This retrospective study was approved by the Institutional Ethics Committee of Chonnam National University Hwasun Hospital and was conducted in accordance with the principles of the Declaration of Helsinki.
: Not applicable
: The authors declare that they have no competing interest.
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