Funding for this research was provided by:
Korea Health Industry Development Institute (HI17C0929)
National Research Foundation (2017M3A9B4042583)
Text and Data Mining valid from 2019-04-23
Received: 11 February 2019
Revised: 11 March 2019
Accepted: 18 March 2019
First Online: 23 April 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: Ethical approval and consent to participate is not applicable to this article as no data were generated or analyzed during the current study.