1. Chungbuk National University Hospital, Cheongju, Chungcheongbuk-do, Republic of Korea
2. Department of Nursing, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
3. Department of Internal Medicine, Chungbuk National University Hospital, Chungbuk National University College of Medicine, Cheongju, Chungcheongbuk-do, Republic of Korea