Funding for this research was provided by:
Korea Centers for Disease Control
Text and Data Mining valid from 2018-05-15
Received: 30 November 2017
Accepted: 30 April 2018
First Online: 15 May 2018
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of Dongguk University (110757-201701-HR-02-03). Both the parents/guardians and the child consented to participating in the study.
: The authors declare that they have no competing interests.
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