Clinical Dementia Rating (CDR) – Dementia severity was determined by total on the Clinical Dementia Rating Scale. The CDR assesses cognitive function in six domains: memory, orientation judgment and problem solving, community affairs and personal care. Based on six scores, a global CDR score is assigned in which CDR 0 indicates no dementia, CDR 0.5 indicates very mild dementia, CDR 1 indicates mild dementia, CDR 2 indicates moderate dementia, and CDR 3 indicates severe dementia.19