1. General Practice Department, The Second Affiliated Hospital, Harbin Medical University, Harbin 150086, China
2. Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin 150001, China
3. Department of Internal Medicine, Harbin Medical University Cancer Hospital, Harbin Medical University, Harbin 150081, China
4. Department of Geriatrics, The Second Affiliated Hospital, Harbin Medical University, Harbin 150086, China