Article History
Received: 20 November 2019
Accepted: 21 January 2020
First Online: 30 January 2020
Ethics approval and consent to participate
: The study was approved in July 2014 by the local Institutional Review Board of Ewha Womans University Hospital, Seoul, Republic of Korea (EUMC 2014–05–032-007). Written informed consent was obtained from participants before inclusion.
: Not applicable.
: The authors declare that they have no competing interests.