Distribution of baseline scores of the Alzheimer's Disease Assessment Scale-Cognitive subscale among the elderly in Beijing / 中华神经科杂志

ABSTRACT

Objective To investigate the distribution pattern of the ADAS-Cog scores among the elderly in Beijing and to evaluate the application of ADAS-Cog in distinguishing patients with mild Alzheimer's disease (AD) and healthy elderly. Methods In total, 1616 healthy elderly (NC), 125 elderly patients with non-AD disorders (ND), and 310 patients with probable AD including 201 patients with mild AD and 109 patients with moderate AD (by NINCDS-ADRDA criteria) were recruited in the study and their cognitive performance was measured by the ADAS-Cog.Results In NC group, those older than 80 years and those with less than 5 years schooling scored highest. There was statistically significant correlation between the total scores of the ADAS-Cog and age and duration of schooling in NC group (F=14.34, 113.27,both P<0.01). No correlation was suggested in the mild AD group. The total score of ADAS-Cog was significantly associated with duration of schooling in both moderate AD and ND groups (F=4.18, 8.72, both P<0.05). The total score of ADAS-Cog differentiated the patients with mild AD from NC healthy elderly with AUC ranging from 0.69 to 0.82 in each subgroup by age, and from 0.75 to 0.88 in subgroups by durations of schooling with the highest AUC of 0.88 in the subgroup having more than 15 years of schooling education. Conclusions The ADAS-Cog score in the healthy elderly is significantly associated with age and duration of schooling education. The ADAS-Cog can be applied in the cognitive assessment of Chinese AD patients. The total score of ADAS-Cog could efficiently differentiate patients with mild AD from healthy elderly, especially in subjects with higher education level.