Text and Data Mining valid from 2018-10-03
Received: 23 August 2017
Accepted: 10 September 2018
First Online: 3 October 2018
Ethics approval and consent to participate
: The study protocol was reviewed and approved by the Institutional Review Board of Seoul National University Bundang Hospital [Reference no. B-1706/401-105]. Since our study is retrospective, participants’ written informed consent was waived and it is also approved by the ethics committee.
: Not applicable
: The authors declare that they have no competing interests.
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