Validation and diagnostic utility of the everyday Cognition (ECOG) in Argentina-ADNI

Abstract

Introduction: The detection and characterization of functional impairments in patients with cognitive impairment is an important clinical and research issue. The Everyday Cognition (ECog) scale is a relatively new informant-rated measure of everyday function. Objective: The objective of this study was to determine the indices of validity and internal consistency of the ECog in the Argentina-Alzheimer´s Disease Neuroimaging Initiative (Arg-ADNI) sample. Methods: We assessed 15 clinically normal elderly (CN), 28 mild cognitive impairment (MCI), and 13 mild Alzheimer´s Disease (AD) dementia subjects from Arg-ADNI. External, convergent and divergent validity and internal consistency were examined. Results: The average total score on the ECog scale was significantly different across the three diagnostic syndromes (p < 0.5). The area under the curve (AUC) for the ECog was .97 (95% CI = .93-.99). The ECog scale was more sensitive than FAQ in discriminating between those with any cognitive impairment (either dementia or MCI) and CN. The ECog scale showed a moderate to strong correlation with other measures of daily function, including the Clinical Dementia Rating (CDR) and the FAQ scales and moderate correlations with neuropsychological tests. Cronbach´s alpha was .98. Co-varying for age or education had no effect on these results. 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.