Patterns of deficits in daily functioning and cognitive performance of patients with Alzheimer disease.

Previous research has identified patterns of cognitive deficits in patients with Alzheimer disease (AD), but little is known about their pattern of daily functional impairment. A total of 49 patients with AD and 52 healthy elderly controls were administered neuropsychological tests as well as the Direct Assessment of Functional Status (DAFS) test, an observation-based test of activities of daily living (ADLs). In this project, we assessed 14 separate tasks assessed by the DAFS. To analyze the data, 4 cognitive domains were created using neuropsychological composite z scores (means and standard deviation obtained from control data) for patients with AD. Results revealed that patients with AD performed worse on the memory, language, and visual-spatial relative to the executive domain. Additionally, patients with AD performed poorer than the controls on nearly all 14 DAFS tasks, with their worse performance being on the shopping-related tasks which, in part, requires memory skills. Logistic regression revealed better specificity than sensitivity classifications based on the DAFS tasks, and stepwise regression analyses indicated that cognitive domains predicted specific aspects of functional abilities. These findings suggest that patients with AD display a distinct pattern of ADLs performance, that traditional neuropsychological tests are useful in predicting daily functioning, and the DAFS has some strengths and weaknesses in classifying AD and controls.