Received: 27 November 2017
Accepted: 17 August 2018
First Online: 10 September 2018
Ethics approval and consent to participate
: This study was approved by the institutional review board at Seoul National University Bundang Hospital, South Korea (IRB no. X-1603/340–903). Consent was not required in this study because the analyzed data were from an existing anonymous questionnaire that was obtained during the pilot operation.
: Not applicable.
: The authors declare that they have no competing interests.
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