1. School of Nursing, College of Nursing, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 06591, Republic of Korea
2. School of Nursing, University of Michigan, 400 North Ingalls Street, Ann Arbor, MI 48109, USA
3. College of Nursing, University of Illinois at Chicago, 845 S. Damen Ave., MC 802, Chicago, IL 60612, USA
4. School of Nursing, University of California, San Francisco, 2 Koret Way, San Francisco, CA 94143, USA