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New 'everyday cognition' scale tracks how older adults function in daily life

July 01, 2008

Short screening test can reveal status of basic mental abilities and follow changes over time

WASHINGTON - As more adults age into the high-risk period for cognitive impairment, clinicians need simple and reliable methods to identify where they may have problems in everyday life that reveal underlying changes in the brain. A new, carefully validated questionnaire called Everyday Cognition (ECog), when filled out by someone who knows an older adult well, can sensitively evaluate the performance of everyday activities that reflect basic mental functioning, according to a report in the July issue of Neuropsychology, published by the American Psychological Association.

Keeping track of things, sorting the mail, following a conversation, shopping for a few things without a list, finding the car in a parking lot - activities such as these, if compromised, could signal the risk for or presence of disease. The quick and easy identification of mild functional problems in older adults could be extremely useful in primary-care settings, where dementia and its early warning signs are frequently missed.

Seven academic and Veterans Administration psychologists, led by co-authors Sarah Tomaszewski Farias, PhD, and Dan Mungas, PhD, of the University of California, Davis, teamed up to develop and validate this new 39-question screening tool. The team first collected data on everyday functioning and mental status for 576 older adults, averaging nearly 77 years old, who were evaluated at the University of California's Alzheimer's Disease Research Center. Of these individuals, 174 were diagnosed as cognitively normal, 126 were diagnosed with Mild Cognitive Impairment (which often develops into dementia), and 276 were diagnosed with dementia (progressive cognitive decline).

The authors also interviewed neurologists, nurses, neuropsychologists and other professionals who work with people with dementia. Building on their insights, Farias and her colleagues generated items describing everyday function in seven key cognitive domains: memory, language, semantic (factual) knowledge, visuospatial abilities, planning, organization and divided attention. Through pilot studies, they narrowed an initial list of 138 items to the 39 items used in the validation study.

To validate the instrument, the new rating scales were completed by reliable informants, people who lived with or knew the patients well. They knew them on average for nearly 45 years and were with them for an average of 75 hours a week. About half the informants were spouses; 41 percent were adult children; the rest were other family members or friends. The average informant was nearly 62 years old and nearly three in four were women.

The authors relied on informants rather than patients because people with dementia lose awareness of their problems. The authors also relied on observation by informants rather than by clinicians because performance assessments, such as watching someone make a peanut-butter-and-jelly sandwich, can be artificial and time-consuming. At the same time, the authors sought to improve on previous informant-based measures, which have been unable to detect mild impairment or track change over time - a "must" for progressive disorders.

The ECog was shown to be valid in several ways. First, its results appeared to measure the same things as established tests, a sign of convergent validity. Second, its results "agreed" with participants' medical diagnoses, a sign of external validity.

By differentiating among people with normal cognition, Mild Cognitive Impairment (MCI), and dementia, the ECog was sensitive to the early functional changes present in MCI. Thus, the authors believe, the ECog shows great promise as a useful screening measure for detecting individuals at increased risk for developing dementia. What's more, its results do not appear to be strongly influenced by the role of education, as is the case in other cognitive tests.

The ECog's results even differentiated between people diagnosed with mild impairment in memory only and those mildly impaired in several areas. This sensitivity could help with differential diagnosis of underlying brain disease.

Because the ECog is sensitive to early functional problems, the researchers hope that it will shed light on how functional problems emerge and, over time, lead to obvious disability. More immediately, the ECog can help clinicians to diagnose cognitive impairment more effectively and to better understand the "limits, care needs and interventions appropriate to individuals." For example, making more lists, relying more on calendars and timers, learning memory techniques for new names, or organizing household papers in a new way might enable independent functioning for a longer length of time.

American Psychological Association