Funding for this research was provided by:
Inje University (2018 research grant)
Received: 22 June 2018
Accepted: 21 July 2019
First Online: 26 July 2019
Ethics approval and consent to participate
: This study was approved by the Sanggye Paik Hospital Clinical Trials Ethics Committee (SGPAIK 201612017). Informed consent was not acquired as this was a retrospective study.
: Not applicable.
: The authors declare that they have no competing interests.