aDepartment of Nursing, Pukyung National University, Busan, Korea
bDepartment of Nursing, Kyungnam University, Changwon, Korea
© 2015 Published by Elsevier B.V. on behalf of Korea Centers for Disease Control and Prevention.
This is an Open Access article distributed under the terms of the CC-BY-NC License (http://creativecommons.org/licenses/by-nc/3.0).