Received: 16 May 2018
Accepted: 28 December 2018
First Online: 8 January 2019
Ethics approval and consent to participate
: The EASS data archive provides publicly available data from anonymous respondents. Verbal informed consent was obtained from all participants, due to the limited time for survey interviews, and waivers of written consent were authorized by an ethics committee. Ethical approval for this study was granted by the institutional review board of the Graduate School of Public Health, Yonsei University, Seoul, Korea (IRB No. 2014–225).
: Not applicable.
: The authors declare that they have no competing interests.
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