Funding for this research was provided by:
Health Promotion Administration, Ministry of Health and Welfare (Grant number: HI14C3229)
Article History
Received: 11 October 2018
Accepted: 9 March 2019
First Online: 14 March 2019
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: The institutional review board of the Samsung Medical Center approved this study. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study, formal consent is not required.