Black-white disparities in functional decline in older persons: the role of cognitive function.
ABSTRACT Black elders have a greater frequency of functional decline than do white elders. The impact of cognitive function on explaining black-white disparities in functional decline has not been extensively explored.
To compare the extent to which different risk domains (comorbidity, smoking, socioeconomic status (SES), self-rated health, and cognitive function) explain more frequent functional decline in black elders, we studied 779 black and 4892 white community-dwelling adults aged 70 and older from the Assets and Health Dynamics Among the Oldest Old (AHEAD), a population-based cohort study begun in 1993. Our primary outcome was worse functional status at 2 years than at baseline. We used logistic regression to compare the unadjusted with the adjusted black-white odds ratios (ORs) after adjusting for each risk domain.
At baseline black participants aged 70-79 had higher rates of smoking, diabetes, and hypertension; lower SES; and worse cognitive function than did white participants (p <.05 for all). The mean cognitive score was 15.7 in black and 21.8 in white participants (p <.01). Black participants had a higher frequency of 2-year functional decline than did white participants (10.9% vs 4.7%; OR = 2.61, 95% confidence interval [CI], 1.69-4.03 adjusted for age and sex). Adjustment for comorbidity and smoking did not significantly change the black-white OR, whereas self-rated health and SES accounted for about half the risk. Adjustment for cognitive function accounted for nearly all the associated decline (OR = 1.10, 95% CI, 0.67-1.79). Among participants aged 80 and over, those who were black had significantly lower risk for functional decline after adjustment for cognitive function (OR = 0.61, 95% CI, 0.38-0.96 vs OR = 1.08, 95% CI, 0.70-1.66 adjusted for age and sex only).
Cognitive function mediated the higher frequency of functional decline among black elders. Efforts to understand cognitive function may enhance our understanding of black-white disparities in health outcomes.
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ABSTRACT: This study examined if reported physical activity has beneficial outcomes on disability through cognitive performance-mediated effects and if these mediation effects are comparable for White and African American elders. Longitudinal data from the Assets and Health Dynamics among the Oldest Old study (N = 4,472) are used to test mediation in multilevel models. During the 7-year follow-up, cognitive performance mediated the effects of reported physical activity on disability in the entire sample and in Whites but not in African Americans. Our results indicate that reported physical activity may delay the disability development through improvement in cognitive performance. Unmeasured education and comorbidity influences may have obscured the mediation effects in African Americans. Reported physical activity plays a key role in the independence of older adults and should be particularly promoted in African Americans and during the entire life course.The Journals of Gerontology Series B Psychological Sciences and Social Sciences 03/2009; 64(1):4-13. DOI:10.1093/geronb/gbn030 · 2.85 Impact Factor
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ABSTRACT: The purpose of the present study was to examine the nature of the relationships among dispositional optimism/pessimism, self-efficacy, and physical function in a cross-sectional sample of older women (N = 249, M age = 69 years). Initial bivariate analyses indicated that both pessimism and self-efficacy, but not optimism, were significantly correlated with objectively measured physical function. Subsequent analyses using covariance modeling with the full-information maximum likelihood estimator indicated that pessimism was no longer correlated with function when controlling for self-efficacy. That is, consistent with a social cognitive perspective, controlling for self-efficacy attenuated the relationship between pessimism and function. Our findings provide support for using a social cognitive perspective to understanding dispositional and modifiable influences on declines in function associated with aging.Journal of Behavioral Medicine 05/2007; 30(2):107-14. DOI:10.1007/s10865-006-9089-9 · 3.10 Impact Factor
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ABSTRACT: The purpose of this study was to utilize the disablement pathway model to examine the contribution of physical function, dyspnea, and pain to disability in activities-of-daily-living (ADL) in culturally diverse older adults. Participants were 51 older adults (age = 69.0 years ± 9.7; 76.5% African-American, 51.0% < high school education, 52.9% < $20,000 annual income) from an urban community center and an independent living housing facility for seniors. Participants completed the Functional Status Index (FSI), which provides ratings of need for assistance (FSIA) and pain (FSIP) with ADL, the Continuous Scale Physical Functional Performance 10-item Test (CS-PFP10), and an analog dyspnea scale. Hierarchical multiple regression analyses revealed that facility, physical function, pain, and dyspnea accounted for 50.5% of the variance in disability and that pain (β = .43, p < .01) and physical function (β = -.39, p < .01) were the only significant predictors. In the second model, facility, dyspnea, and pain explained 27.6% of the variance in physical function, and facility (β = .39, p < .01) and dyspnea (β = -.26, p = .05) were the only significant predictors. Based on the disablement pathway model, physical functional improvement and pain prevention and management should be targeted when designing culturally appropriate strategies for delaying disability and maintaining independent life.