The characteristics of patients with uncertain/mild cognitive impairment on the Alzheimer disease assessment scale-cognitive subscale

The performances of the uncertain/mild cognitive impairment (MCI) patients on the Alzheimer Disease Assessment Scale-Cognitive (ADAS-Cog) subscale were compared with those of normal controls, Alzheimer disease patients with CDR 0.5, and Alzheimer disease patients with CDR 1.0. The Uncertain/MCI group was significantly different from normal controls and Alzheimer disease CDR 0.5 or 1.0 groups on the ADAS-Cog except on a few non-memory subtests. Age was significantly correlated with total error score in the normal group, but there was no significant correlation between age and ADAS-Cog scores in the patient groups. Education was not significantly correlated with the ADAS-Cog scores in any group. Regardless of age and educational level, there were clear differences between the normal group and the Uncertain/MCI group, especially on the total error scores. We found that the total error score of the ADAS-Cog was the most reliable variable in detecting patients with mild cognitive impairment. The present study demonstrated that the ADAS-Cog is a promising tool for detecting and studying patients with mild cognitive impairment. The results also indicated that demographic variables such as age and education do not play a significant role in the diagnosis of mild cognitive impaired patients based on the ADAS-Cog scores.