Funding for this research was provided by:
Korea Centers for Disease Control & Prevention (2011E3300300, 2012E3301100, 2013E3301600, 2013E3301601, 2013E3301602, and 2016E3300200)
Text and Data Mining valid from 2019-04-03
Received: 30 September 2017
Accepted: 17 March 2019
First Online: 3 April 2019
Ethics approval and consent to participate
: The study protocol was approved by the ethical committee of each participating clinical center, including the Institutional Review Boards of Seoul National University Hospital, Severance Hospital, Kangbuk Samsung Medical Center, Seoul St. Mary’s Hospital, Gil Hospital, Eulji General Hospital, Chonnam National University Hospital, and Busan Paik Hospital. All participating patients provided written informed consent. The study protocol was in accordance with the principles of the Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.
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