Kim, Seung Hyun
Na, Sungwon
Lee, Woo Kyung
Choi, Hyunwoo
Kim, Jeongmin http://orcid.org/0000-0002-0468-8012
Article History
Received: 24 August 2017
Accepted: 8 March 2018
First Online: 2 April 2018
Ethics approval and consent to participate
: Severance Hospital Institutional Review Board approval was obtained for both the questionnaire survey and retrospective study. Written informed consent was obtained from all responders in the survey.
: Not applicable.
: The authors declare that they have no competing interests.
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