Funding for this research was provided by:
National Research Foundation of Korea (2017M3A9E8029714)
Text and Data Mining valid from 2019-04-11
Received: 25 November 2018
Accepted: 25 March 2019
First Online: 11 April 2019
Ethics approval and consent to participate
: This study was approved by the institutional review board of Severance Hospital at Yonsei University College of Medicine (No. 4–2018-0518) and was performed in accordance with the Declaration of Helsinki and the International Conference of Harmonization Good Clinical Practice Guidelines. The requirement to obtain a written informed consent was waived by the institutional review board of Severance Hospital at Yonsei University College of Medicine because our study was retrospective research based on medical records, and this research presented no more than minimal risk of harm to subjects.
: Not applicable.
: The authors declare that they have no competing interests.
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