1. Department of Healthcare Management, Eulji University, Seongnam, Korea
2. Department of Rehabilitation Standadard and Policy, Rehabilitation Research Institute, Korea National Rehabilitation Center, Seoul, Korea
3. Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
4. Department of Preventive Medicine, Kyung Hee University School of Medicine, Seoul, Korea
5. Department of Humanities and Social Medicine, College of Medicine and Catholic Institute for Healthcare Management, the Catholic University of Korea, Seoul, Korea