1. Department of Family Medicine, Kangdong Sacred Heart Hospital, Hallym University, Seoul, Korea
2. Department of Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea
3. Department of Family Medicine/Supportive Care Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
4. Depression Center, Department of Psychiatry, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
5. Department of Clinical Research Design & Evaluation, Samsung Advanced Institute for Health Science & Technology, Sungkyunkwan University, Seoul, Korea
6. Department of Physical & Rehabilitation Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
7. Department of Family Medicine, Seoul National University Hospital Healthcare System Gangnam Center, Seoul, Korea
8. Department of Statistics and Actuarial Science, Soongsil University, Seoul, Korea