1. Graduate School of Public Health, Yonsei University, Korea.
2. Institute of Health Services Research, Yonsei University, Korea.
3. Clinical Trials Center, Severance Hospital, Yonsei University Health System, Korea.
4. Department of Public Health, Graduate School, Yonsei University, Korea.
5. Health Insurance Review & Assessment Services, Korea.
6. Department of Orthopedics, College of Medicine, Yonsei University, Korea.