1. Department of Family Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan
2. Chang Gung University College of Medicine, Taoyuan, Taiwan
3. Department of Family Medicine, Chang Gung Memorial Hospital, Linkou
4. Department of Family Medicine, Taipei Medical University Hospital and School of Medicine, Taipei Medical University, Taipei, Taiwan
5. Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan