Prediction of functional status from neuropsychological tests in community-dwelling elderly individuals

Age-related dysfunction of frontal systems can result in deficits in planning, organization, self-control, and awareness of problems, which are likely to affect the ability to care for one's self. The purpose of this study was to determine the relationship between age-related frontal/executive deficits and impairment in instrumental activities of daily living (IADLs) in elderly individuals. Twenty-seven community-dwelling individuals were administered a comprehensive battery of neuropsychological tests and a performance-based evaluation of IADLs. Multiple regression analyses indicated that executive function and depression severity accounted for a significant proportion of variance in IADLs, with executive function making the greatest contribution. Tests measuring other cognitive functions, such as memory, language, and spatial skills, did not contribute significantly to the prediction of functional status. Furthermore, executive measures accounted for more variance than other demographic characteristics such as general health status, age, and educational level. The results of this study indicate that executive dysfunction in normal aging may be the best predictor of functional decline. A better understanding of the mechanisms that underlie IADL skills will ultimately aid in the development of compensatory and intervention strategies designed to delay the onset of assisted living and nursing home placement.