Funding for this research was provided by:
Korean Medical Association
Text and Data Mining valid from 2018-04-25
Received: 1 November 2017
Accepted: 16 April 2018
First Online: 25 April 2018
Ethics approval and consent to participate
: This study was exempted from ethical approval by the Institutional Review Board designated by Korean Ministry of Health and Welfare (P01-201711-21-017).
: The authors declare that they have no competing interests.
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