摘要：Objectives. We investigated whether a greater burden of disease among poorer individuals and ethnic minorities accounted for socioeconomic and racial disparities in self-reported physical functioning among older adults. Methods. We used data from adults aged 60 years or older (n = 5556) in the Third National Health and Nutrition Examination Survey, 1988–1994 to test associations between education level, poverty index, and race/ethnicity and limitations in 11 functions. We adjusted for demographic features and measures of disease burden (comorbid conditions, smoking, hemoglobin level, serum albumin level, knee pain, body mass index, and skeletal muscle index). Results. Associations between education and functional limitations were attenuated after adjustment, but those with 0–8 years of education were more likely than those with 13 or more years of education to have limitations in 3 functions. Poverty was associated with a higher likelihood of limitations despite adjustment. The likelihood of limitations among non-Hispanic Blacks and Mexican Americans was similar to that of non-Hispanic Whites after adjustment. Conclusions. Socioeconomic disparities in functional limitations among older Americans exist independent of disease burden, whereas socioeconomic differences and disease burden account for racial disparities. Although the prevalence of disability among older adults in the United States has generally declined over the past decade, this trend has not extended to all segments of the population. 1 – 4 Disability among ethnic minorities and economically disadvantaged groups has not declined, resulting in widening ethnic and socioeconomic disparities. 5 – 11 Racial minorities and those who are economically disadvantaged are up to 3 times more likely to experience disability than are Whites and those who are not economically disadvantaged, respectively. 8 , 10 , 12 , 13 Achieving health equity has been a public policy priority, and collective interventions have been proposed. 12 , 14 , 15 Functional limitations in older adults are particularly important because of their prognostic and economic implications. 16 Functional limitations predict further future decline in physical function, 17 an increased risk of dementia, 18 loss of independence, institutionalization, and mortality. 19 – 21 According to the Institute of Medicine model of the enabling–disabling process, disability is a product of the complex interactions between a person and his or her psychological, social, and physical environments. 22 In this context, functional limitations are partly a consequence of an individual's burden of disease. Musculoskeletal conditions, chronic neurological and cardiopulmonary disorders, sensory and cognitive deficits, anemia, sarcopenia, and chronic pain may lead to functional limitations and disability. Many of the chronic health conditions that can affect physical functioning are more common among ethnic minorities and economically disadvantaged groups, 5 , 6 , 9 – 12 raising the question of whether a greater burden of disease can primarily explain the higher prevalence of functional limitations and disability in these groups. Previous studies of socioeconomic and ethnic disparities in functional limitations reported unadjusted data or data adjusted only for differences in demographic characteristics. 10 , 11 , 23 – 27 Few studies have examined the role of differences in comorbid conditions, obesity, or smoking or simultaneously examined a range of indicators of disease burden. 6 , 9 , 28 We sought to determine whether socioeconomic and ethnic differences in functional limitations among noninstitutionalized older adults in the United States remain after adjusting for measures of disease burden.
