Text and Data Mining valid from 2019-01-07
Received: 13 March 2018
Accepted: 7 December 2018
First Online: 7 January 2019
Ethics approval and consent to participate
: These data were approved by the KCDC Institutional Review Board, and all participants provided written informed consent (2010-02CON-21-C, 2011-02CON-06-C, 2012–01-EXP-01-2C, 2013-07CON-03-4C, and 2014-12EXP-03-5C).
: Not applicable.
: The authors declare that they have no competing interests.
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