1. Department of Public Health; Graduate School; Yonsei University; Seoul Korea
2. Institute of Health Services Research; Yonsei University; Seoul Korea
3. Research and Analysis Team; National Health Insurance Service Ilsan Hospital; Gyeonggi-do Korea
4. Department of Health Administration; Soonchunhyang University; Chungcheongnam-do Korea
5. Department of Preventive Medicine; Yonsei University College of Medicine; Seoul Korea