The comprehensive assessment of community dwelling elderly: why functional status is not enough

The present study attempts to determine empirically the relationship of measures of functional status to other domains common to geriatric assessment, and to ascertain whether functional status can substitute for other domains of clinical assessment. A comprehensive research survey was administered in the home to a randomly selected population of 4163 community residents aged 65 and over in the Duke EPESE, one of the four sites of the National Institute on Aging-funded Established Populations for Epidemiologic Studies of the Elderly. Sample members were predominantly black (55%), female (65%), between 65 and 74 years of age (61%), and lived in five contiguous counties within the state of North Carolina. Measurements included three measures of functional status ranging from basic activities of daily living (ADL) to strenuous mobility items, and summary measures of cognition, depression, and overall physical health. The three functional status measures were inter-correlated. However, with the exception of cognitive status and performance of instrumental ADL, the functional status measures failed to show a clinically significant relationship with the domains of cognition, depression, or overall physical health status. Furthermore, even among those sample members impaired in all three domains, 8% could still perform strenuous activities, and over 50% could still perform the basic activities of daily living. The data show that functional status measures are not necessarily indicative of an elder's mental or physical health. Each domain of assessment contributes unique data, and no one area can fully substitute for another.