a Department of Neurology, Chi-Mei Medical Center, Tainan, Taiwan b Institute of Clinical Medicine, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan c Biostatistics Consulting Center, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan d Department of Internal Medicine, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan e Department of Occupational Safety and Health, Institute of Industrial Safety and Disaster Prevention, College of Sustainable Environment, Chia Nan University of Pharmacy and Science, Tainan, Taiwan