1. Institute of Gerontology, College of Medicine, National Cheng Kung University , Tainan 701401 , Taiwan
2. Department of Family Medicine, College of Medicine, National Cheng Kung University , Tainan 701401 , Taiwan
3. Department of Family Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University , Tainan 704302 , Taiwan
4. Institute of Allied Health Sciences, College of Medicine, National Cheng Kung University , Tainan 701401 , Taiwan