Funding for this research was provided by:
National Research Foundation of Korea (2017R1D1A1B03033771)
Article History
Received: 10 October 2019
Accepted: 28 April 2020
First Online: 7 May 2020
Ethics approval and consent to participate
: Since this study does not collect and record personal identification information using information disclosed to the public, a review exemption was approved by Eulji University human research ethics committees (EUIRB2018–18). The use of big data for this study was approved by the National Health Insurance Service (NHIS-2019-1-028).
: Not applicable.
: The authors declare that they have no competing interests.