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Article History

Received: 11 October 2019

Accepted: 24 April 2020

First Online: 7 May 2020

Compliance with ethical standards

:

: The authors declare that they have no conflict of interest.

: Ethics approvals for the study protocol and analysis of the data were obtained from institutional review board of Kangbuk Samsung Hospital.

: Informed consent was not required because we only assessed retrospective data without presonal identifying information.