Funding for this research was provided by:
Chungnam National University (2020-0637-01)
Received: 3 July 2020
Accepted: 11 December 2020
First Online: 6 January 2021
Ethics approval and consent to participate
: The study was approved by the institutional review board of Chungnam National University Hospital (IRB File No. CNUH 2016–10–029-001). The study objectives were explained to the participants and written consent was obtained before each interview.
: Not applicable.
: The authors declare that they have no competing interest.