1. College of Nursing, Ewha Womans University, Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Republic of Korea
2. School of Nursing, Duke University, 307 Trent Drive, DUMC 3322, Pearson Building, Durham 27710, USA
3. Department of Nursing, Semyung University, Jecheon-si, Chungbuk, Republic of Korea
4. College of Nursing, Ewha Womans University, 52, Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Republic of Korea