Funding for this research was provided by:
Chonbuk National University Hospital
Received: 12 March 2018
Accepted: 4 October 2018
First Online: 20 October 2018
Ethics approval and consent to participate
: This is a retrospective study with ethically approved by the institutional review board of Chonbuk National University Hospital (No. 2013–08-024). This study is retrospective study, therefore we exempted the consent to participate.
: Not applicable.
: The authors declare that they have no competing interests.
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