Funding for this research was provided by:
Ministry of Science, Information & Communication Technology, and Future Planning (2014R1A2A2A01002421)
Received: 27 March 2019
Accepted: 30 August 2019
First Online: 7 September 2019
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board (IRB) of Severance Hospital (No.2015–0917-007) and Bundang CHA Medical Center (No.2017–09-029) with written informed consent being obtained from the participants and/or their parents/guardians according to rules of the Ethics Committee.
: Not applicable.
: The authors declare that they have no competing interests.