Text and Data Mining valid from 2019-07-16
Received: 20 December 2018
Accepted: 28 May 2019
First Online: 16 July 2019
Ethics approval and consent to participate
: This study received ethics approval from the Institutional Review Board of Pusan National University Hospital in Korea. Written informed consent was obtained from each participant when survey were conducted.
: Not applicable.
: The authors declare that they have no competing interests.