Article History
Received: 22 July 2018
Accepted: 22 April 2019
First Online: 2 May 2019
Ethics approval and consent to participate
: Ethics approval was obtained following project approval by the National Health Insurance Service Ilsan Hospital (NHIMC 2015–02-015). The need for written consent was formally waived by the ethics committee.
: Not Applicable.
: The authors declare that they have no competing interests.
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