1Department of Trauma and Emergency Surgery, Chang Gung Memorial Hospital, 5 Fu-Shin Street, Kwei-Shan, Tao-Yuan, Taiwan, ROC
2Center for Health Industry Management and Public Policy, Department of Health Care Management, Chang Gung University, 259 Wen-Hu 1st Road, Kwei-Shan, 333, Tao-Yuan, Taiwan, ROC
3Center for Gerontological Research, School of Nursing, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, 333, Tao-Yuan, Taiwan, ROC
4Department of Public Health, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, 333, Tao-Yuan, Taiwan, ROC
5Health Management and Policy, School of Public Health, M3234 School of Public Health II, University of Michigan, Ann Arbor, MI 48109-2029, USA
6Department of Orthopedics, Chang Gung Memorial Hospital, 5 Fu-Hsin Street, Kwei-Shan, Tao-Yuan, Taiwan, ROC