Funding for this research was provided by:
National Research Foundation of Korea (NRF-2014R1A1A1006809)
National Research Foundation (No. 2020R1F1A1057423)
Received: 29 August 2020
Accepted: 4 May 2021
First Online: 17 May 2021
: This study was conducted in accordance with the Declaration of Helsinki, and the study protocol was reviewed and approved by the Institutional Review Board of Keimyung University Daegu Dongsan Hospital (2015-09-020-003) and Kyungpook National University (2015-87). Informed consent was included with each questionnaire and introduced before the surveys. Surveys were conducted only if participants were fully informed of the content and aim of this research project and agreed to participate.
: Not applicable.
: The authors declare that they have no competing interests.