Funding for this research was provided by:
Yonsei University College of Medicine (6-2012-0022)
Received: 2 April 2018
Accepted: 7 February 2020
First Online: 21 February 2020
Ethics approval and consent to participate
: Ethical approval for the study is deemed unnecessary according to the provision of subparagraph 2 in paragraph (2) in Article 2 of the Enforcement Regulations of the Bioethics and Safety in the Health-Welfare Ministry in South Korea since the study represents <i>normal educational practice in the educational institution</i> designated and notified by the Minister of Health and Welfare. For consent to participate, participants were asked to read and sign an informed consent form that explained that participation in this study was voluntary and that participants could decline to participate at any time.
: Not applicable
: The authors declare that they have no competing interests.