Funding for this research was provided by:
Korea Centers for Disease Control and Prevention (2011E3300300, 2012E3301100, 2013E3301600, 2013E3301601, 2013E3301602, and 2016E3300200)
Received: 16 January 2020
Accepted: 6 July 2020
First Online: 16 July 2020
Ethics approval and consent to participate
: The study protocol was approved by the Institutional Review Board at each participating clinical center [Seoul National University Hospital (1104–089-359), Seoul Navtional University Bundang Hospital (B-1106/129–008), Yonsei University Severance Hospital (4–2011-0163), Kangbuk Samsung Medical Center (2011–01-076), Seoul St. Mary’s Hospital (KC11OIMI0441), Gil Hospital (GIRBA2553), Eulji General Hospital (201105–01), Chonnam National University Hospital (CNUH-2011-092), and Busan Paik Hospital (11–091)]. Written informed consent was obtained from each patient.
: Not applicable.