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OBJECTIVES: To investigate the association between cognitive ability and physical performance in a population-based sample of middle-aged African Americans. DESIGN: Cross-sectional study, 2000/2001. SETTING: St. Louis, Missouri. PARTICIPANTS: Nine hundred ninety-eight African Americans born between 1936 and 1950. MEASUREMENTS: Cognitive function was measured using the Mini-Mental State Examination (MMSE) and the Animal Naming Test of verbal fluency. Physical performance was measured using eight tests: chair stand, semitandem stand, tandem stand eyes open, tandem stand eyes closed, one-leg stand, usual gait speed, grip strength, and peak expiratory flow. RESULTS: There was a statistically significant and monotonic (progressively worsening) trend of the eight physical performance measures across cognitive tertiles in all eight MMSE analyses and five of eight Animal Naming analyses, controlling for age, sex, education, geographic area, depressive symptoms, and comorbid conditions. CONCLUSION: The association between physical performance and cognitive function appears robust. The results extend previous reports for adults aged 65 and older to a measure of verbal fluency and to a population-based sample of African Americans aged 49 to 65. Further research is needed to disentangle the temporal sequence and identify potential interventions to prevent declines in function. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Subclinical status for functional limitation and disability help explain pathways to difficulties with functional limitation and disability, but data on their measurement stability are minimal. We evaluated the reproducibility of measuring subclinical status in a random subset of 92 community-dwelling St. Louis African Americans aged 49 to 65 years old. METHODS: We examined test-retest reliability of subclinical status using Fried's measurement method of changing either the frequency or method of task performance for five functional limitations, three basic activities of daily living (ADLs), and four instrumental ADLs, as well as summary scales reflecting these three constructs. We also performed sensitivity analyses of test-retest interval and alternative definitional approaches (using only method, only frequency, or both). RESULT: Weighted kappas for individual tasks across three performance levels (high functioning, subclinical status, and task difficulty) indicated moderate agreement for one task and substantial agreement for 11 tasks. Intraclass correlation coefficients for the three scales demonstrated outstanding agreement. The most reproducible definition of subclinical status involved the either/or method. DISCUSSION: Excellent test-retest reproducibility was demonstrated in this population-based sample of late middle-aged African Americans using Fried's method of measuring subclinical status. [ABSTRACT FROM AUTHOR]

OBJECTIVES: In this article we explore the measurement properties of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) in 49- to 65-year-old African Americans, compare their health-related quality of life (HRQoL) with that of the nation, and evaluate the association of selected covariates with HRQoL. METHODS: A probability sample of 998 African Americans in St. Louis received comprehensive in-home assessments. We used an item analysis, exploratory and confirmatory factor analysis, and internal consistency reliability to evaluate the measurement properties of the eight SF-36 scales and their interrelationships. We used a multiple linear regression analysis to characterize the effects of the demographic, socioeconomic status, psychosocial attributes, and biomedical markers. RESULTS: Assessments averaged 2.5 hr. Each SF-36 scale was unidimensional, all items had robust factor loadings, and all but one scale achieved excellent (alpha > or = .80) internal consistency reliability levels. The overall factor structure of the SF-36 scales was generally consistent with national norms. Substantial variance was explained by the covariates, mostly attributable to socioeconomic status and the biomedical markers. CONCLUSIONS: The SF-36 is a reliable and valid measure of HRQoL for use with African Americans. In this sample, the HRQoL was below national averages. Future social epidemiologic studies should include grip strength, vision, and hearing assessments, which had substantial and consistent associations with the SF-36 scale scores. [ABSTRACT FROM AUTHOR]