Association between executive attention and physical functional performance in community-dwelling older women.

OBJECTIVES: Executive functions supervise the contents of working memory, where information from long-term memory is integrated with information in the immediate present. This study examined whether executive attentional abilities were uniquely associated with the performance of complex, instrumental activities of daily living (IADLs) in cognitively intact and physically high-functioning older women.
METHODS: Participants were 406 community-residing, older women aged 70-80 years in the Women's Health and Aging Study (WHAS) II, screened to be physically high functioning and cognitively intact using the Mini-Mental State Exam. Hierarchical regression models, adjusted for demographic and disease variables, were used to evaluate the association of cognitive domains, including executive attention, memory, psychomotor speed, and spatial ability with summary measures of IADL (e.g., looking up and dialing a telephone number) and mobility-based ADL (e.g., walking 4 meters) function.
RESULTS: Tests of executive attention were associated with performance on IADLs (6.6%) and, to a lesser degree, mobility-based ADLs (1%), adjusting for demographic and disease variables. In particular, the mental flexibility component of the Trail Making Test accounted for the majority of attentional variance in IADL performance. Older age, lower education, and African American race were also associated with poorer physical test performances. DISCUSSION: Executive difficulties in flexibly planning and initiating a course of action were selectively associated with slower performance of higher-order IADL tests, relative to other domains of cognition, in a high-functioning, community-based older cohort. These results suggest that executive functions may be important in mediating the onset and progression of physical functional declines.