RESUMO
INTRODUCTION: The performance of activities of daily living in elderly patients with memory disorders is directly related to living independently and to autonomy. Documenting and assessing functional capacity through detailed scales is important for both diagnostic and treatment recommendations. The Everyday Cognition (ECog) scale is a relatively new informant-rated measure of cognitive and functional abilities. In the present study, the discriminant validity of the ECog scale was evaluated in cognitively intact controls (CN) and in patients with mild cognitive impairment (MCI) and mild Alzheimer's disease (AD) from the Argentina-ADNI cohort to establish diagnostic accuracy. In addition, we compared the sensitivity and specificity of ECog against Functional Assessment Questionnaire (FAQ) scale to discriminate among the three groups. METHODS: We evaluated 15 CN, 28 MCI, and 13 mild AD subjects. External, convergent and divergent validity and internal consistency were examined. RESULTS: The average total score on the ECog was significantly different across the three diagnostic syndromes (p < .05). The ECog was more sensitive than FAQ in discriminating between CN and MCI patients and between MCI and AD subjects. The ECog showed a strong correlation with FAQ, and moderate correlations with neuropsychological tests. Cronbach's alpha was .98. CONCLUSIONS: The ECog scale is an efficient instrument for the differentiation of individuals with mild dementia or MCI from normal older adults, with good accuracy and good correlation with other tests measuring daily and cognitive functions. Comparing against FAQ, ECog was more useful in assessing changes in functionality in MCI patients.