Life-Space and Cognitive Decline in a Community-Based Sample of African American and Caucasian Older Adults

Abstract

Background Life-space, a measure of movement through one’s environment, may be viewed as one aspect of environmental complexity for older adults. We examined the relationship between life-space and subsequent change in cognitive function. Methods Participants were 624 community-dwelling Medicare beneficiaries (49% African American) who completed in-home assessments at baseline and follow-up 4 years later. The Life-Space Assessment was used at baseline to measure extent, frequency, and independence of participants’ movement within and outside the home. Cognitive decline was measured with the Mini-Mental State Examination (MMSE). Results In a regression model adjusted for baseline MMSE, age, gender, race, residence (rural/urban), and education, greater life-space at baseline predicted reduced cognitive decline (β = −.177, p < .001). This association remained statistically significant in subsequent models that examined what proportion of the observed association was explained by baseline physical activity, physical function, vascular risk factors, comorbidity, and psychosocial factors. Physical function accounted for the largest proportion (37.3%) of the association between life-space and cognitive decline. There was no significant interaction between life-space and race, gender, or age in predicting cognitive decline. In a logistic regression analysis, participants in the highest quartile of life-space had 53% reduced odds of substantial cognitive decline (≥4 points on MMSE) compared to those in the lowest quartile. Conclusions These preliminary findings suggest that life-space may be a useful identifier of older adults at risk for cognitive decline. Future research should investigate the potential reciprocal relationship between life-space and cognitive function as well as the interrelationship between these factors and physical function.

Life-Space Mobility of Older Adults Living in the Community – A Cross-Sectional Study

“…The participants' mean LSA composite score was 48.73. In most other studies assessing older people's LSA, the mean LSA composite score was higher (1,3,5,6), ranging from 62.9 (3) to 69.8 (5). In one study (7), the mean LSA composite score was lower than that in the current study.…”

“…As a restricted life space has been found to be associated with older age (1,7,9), the lower LSA score in the present study is likely a result of the higher mean age of the participants. Moreover, in our study, the participants apparently represented a more vulnerable population than the communitydwelling older adults in other studies (1,3,5). However, we could not compare our results on health and functional outcomes with those of previous studies because different measures were used across studies.…”

“…A more recent life-space assessment instrument, the life-space assessment (LSA), was developed for the University of Alabama at Birmingham (UAB) Study (3). In most studies measuring older people's life space using the LSA, the participants' mean LSA composite scores were approximately half of the maximum score of 120 (1,3,5,6),although one study (7)found a lower composite score (41.7). Factors associated with a restricted life space include female gender (1,7,8), old age (1,7,9), poor scores on the ADL scale (1,7,9,10), less physical activity, depression (1,7,8), and cognitive decline (1,5).We posit that in addition to these factors, individuals' care dependency levels, based on German statutory care insurance, and their utilization of care (professional or lay) could be associated with the restriction of their life space.…”

Barriers to outdoor physical activity and unmet physical activity need in older adults

“…The extent of life-space plays a key role in leading an active lifestyle: larger life-space is associated with active social participation (Barnes et al 2007) and may have a protective effect against cognitive decline (Crowe et al 2008). On the other hand, shrinking lifespace can reflect forthcoming or existing problems in older people's lives.…”

“…A relationship between SES and cognitive functioning has also been confirmed in that higher education protected from mild cognitive impairment and Alzheimer's disease (Sattler et al 2012) whereas low SES was associated with increased risk for cognitive impairment and Alzheimer's disease (Atti et al 2010, Karp et al 2004). The association between cognitive capacity and life-space mobility has also been explored: a larger life-space can include more complex environmental structures which can help preserve cognitive capacity (Crowe et al 2008) whereas impaired cognition can result in restricted life-space mobility (James et al 2011).…”