Text and Data Mining valid from 2018-06-05
Received: 29 May 2017
Accepted: 23 May 2018
First Online: 5 June 2018
Ethics approval and consent to participate
: This study was confirmed in the ethical guidelines of the World Medical Association Declaration of Helsinki, and was approved by the Institutional Review Board of SNUH (Approval number 1605–052-760). The requirement for informed consent from patients was waived.
: The authors declare that they have no competing interests.
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