To construct and validate a mini-battery to discriminate between Alzheimer's disease (AD) and mild cognitive impairment (MCI) in patients seen at a hospital memory clinic.
In a cohort of 310 subjects (137 with MCI and 173 with AD), the area under the receiver operating curve (AUC) was used to select the neuropsychologic diagnostic test battery subtests with the best overall performance, namely, the Mini-Mental State Examination (MMSE, 0.715), Logical Memory II (LMII, 0.721), Verbal Fluency Test (0.747), and Lawton index (0.742). A mini-battery test was constructed with the following formulation: FMLL = [(Fluency Test/17 + MMSE/30 + LMII/32 + Lawton/8)/4] x 100. Another cohort of 87 subjects with MCI and 100 with AD was used to validate the mini-battery and to calculate the psychometric properties.
The concurrent validity with Reisberg's Global Deterioration Scale was r = 0.792 (p < 0.001). Cronbach's alpha internal consistency was 0.6358. The AUC to diagnose MCI or AD was 0.879 (95% CI: 0.832-0.927; p < 0.001). Specificity for MCI diagnosis was 0.9 when FMLL scores were above 59% and 1 when scores were above 76%.
The FMLL mini-examination is a useful tool to differentiate between MCI and AD in patients seen in a memory clinic.