Received: 11 December 2020
Accepted: 22 September 2021
First Online: 19 October 2021
: This study was approved by the Institutional Review Boards at all participating hospitals. All participants’ parents provided written informed consent. The IRB numbers of the participating hospitals are as follows: 1–2015-0097 at Yonsei University, Health System, Severance Hospital, Seoul, Republic of Korea; EMC2017–05-002 at Eulji University Hospital, Daejeon, Republic of Korea; and SRH2017R-02 at Seoul Rehabilitation Hospital, Seoul, Republic of Korea. The study was conducted in accordance with The Code of Ethics of the World Medical Association (Declaration of the Helsinki) for the involvement of humans.
: Not applicable.
: The authors declare that they have no competing interests.