Funding for this research was provided by:
Ministry of Health and Welfare in Korea (HI18C0275)
Text and Data Mining valid from 2019-08-14
Received: 15 April 2019
Accepted: 7 August 2019
First Online: 14 August 2019
Ethics approval and consent to participate
: This study was approved by the Ethics Committee of Catholic Medical Center and was performed according to the Declaration of Helsinki.
: Not applicable
: The authors declare that they have no competing interests.