Received: 3 August 2018
Accepted: 8 February 2019
First Online: 13 February 2019
Ethics approval and consent to participate
: The disease surveillance data used in this study is provided publicly by the NNDSS website by the KCDC and does not require any permission. This study was reviewed by the Institutional Review Board of the Korea National Institute for Bioethics Policy and it was confirmed that the utilization of the disease surveillance data did not require oversight by an ethics committee (P01–201808–21-003).
: Not applicable.
: The author declares that he has no competing interests.
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