Screening for amnestic mild cognitive impairment and early Alzheimer's disease with M@T (Memory Alteration Test) in the primary care population

Abstract

To design and validate a new screening test for amnestic Mild Cognitive Impairment (A-MCI) and early stage Alzheimer's disease (AD). We develop a verbal episodic and semantic memory test: the Memory Alteration Test (M@T). Discriminative validity was assessed in a population sample of 400 aged individuals from primary care population centres in Barcelona, Spain, 50 patients with A-MCI according to Petersen et al. criteria, and 66 with early AD (Global Deterioration Scale-4 stage) according to the NINCDS-ADRDA criteria. The M@T is quick, 5-min, and easy to administer and to score. M@T mean scores were significantly different between all groups: 41.4 (SD = 4.9) in the primary care population, 31.5 (SD = 3.9) in the A-MCI group and 21.8 (SD = 4.9) in early AD. A cut-off score of 37 points had a sensitivity of 96% and a specificity of 79% for A-MCI diagnosis (AUC = 0.932). A cut-off score of 28 points had a sensitivity of 92% and a specificity of 98% for early AD diagnosis (AUC = 0.99) and a sensitivity of 87 % and specificity of 82% to differentiate between A-MCI and AD patients. The M@T provides efficient and valid screening for A-MCI and early stage AD, and discriminates between A-MCI and early AD patients.