Funding for this research was provided by:
the Ministry of Education, Science and Technology (NRF2016R1D1A1B03935848)
Received: 29 September 2019
Accepted: 17 January 2020
First Online: 28 January 2020
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of Gangneung Asan Hospital (2016-06-13). All procedures were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1964 and later versions. Informed consent to be included in the study was written and obtained from all patients.
: Not applicable.
: The authors declare that they have no competing interests.