How to ID risk for functional decline: screen with test of executive function.
Functional decline, as reflected in difficulty performing routine activities of daily living, is common in the nondemented elderly. Previously identified risk factors for functional decline in nondemented individuals include age, female gender, depression, social isolation, physical inactivity, medical co-morbidities, and cognitive impairment.
Clinicians generally screen for increased future risk of functional decline using a global measure of cognitive function, such as the easily administered Modified Mini-Mental Status Exam (3MS).
This study shows, however, that executive function--the term psychologists apply to the mental processes involved in planning and goal-directed behavior--is fundamental to the performance of activities of daily living. And the Trail Making Test Part B, a commonly used measure of executive function, turns out to have more predictive value than the 3MS, said Dr. Johnson of the memory and aging center at the University of California, San Francisco.
She reported on 7,717 elderly community-dwelling women who participated in the prospective Study of Osteoporotic Fractures. At baseline, 12% of the women displayed impaired executive function, as defined by a Trail Making Test Part B score more than one standard deviation below the mean, but no impairment of global cognition. Another 5% showed impaired global cognition based upon a 3MS score below 23, but not impaired executive function. Finally, 3% of study participants showed baseline impairment on both tests.
At baseline, women with impaired executive function only, as well as those with both impaired executive function and a poor score on the 3MS, displayed significantly greater functional impairment in terms of a standard activities of daily living scale, compared with those women without impairment on either test or women with impairment only on the 3MS. The activities of daily living included in the scale were dressing, walking two to three blocks, washing up, and getting in and out of bed.
The same pattern held true with regard to a separate instrumental activities of daily living scale that assessed more complex daily activities: preparing meals, performing heavy housework and other chores, and shopping for groceries and clothes.
Moreover, after 6 years of prospective follow-up, those women with baseline impairment only on the Trail Making Test Part B were 1.9-fold more likely to have developed new impairment in activities of daily living than were those without baseline impairment in executive function or global cognition. This was similar to the 2.1-fold increased risk among women with baseline impairment on both the 3MS and Trail Making Test Part B.
In contrast, women with baseline impairment only on the 3MS had a statistically nonsignificant 1.2-fold increased odds of developing new impairment in activities of daily living during 6 years of follow up, Dr. Johnson continued.
Similarly, women with baseline impairment on both the 3MS and the Trail Making Test Part B and those with impairment only on the Trail Making Test Part B had a significantly increased risk of developing new impairment on the instrumental activities of daily living scale during the follow-up period she said.
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|Title Annotation:||Women's Health|
|Publication:||Family Practice News|
|Date:||Jun 15, 2004|
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