Physical Function Assessment in a Community-Dwelling Population of U.S. Chinese Older Adults

Physical function is a critical indicator of the current health status of older adults. As gerontological studies suggest, understanding physical function of older adults, especially the assessment of specific activities and tasks in which impairment threatens one’s ability to live independently, is important from many perspectives. First, physical function is a valid predictor of subsequent disability, and is prognostic of future health needs and social care use (1). Second, impairment in physical function has been associated with substantial morbidity and mortality (2,3). Third, the number of older adults is notable and growing, particularly with respect to minority populations. There is growing evidence that the U.S. immigrant population is graying with more physical function impairment and disabilities in comparison with their U.S.-born counterparts (4). The rapidly increasing minority population is of concern to policymakers allocating resources for culturally and linguistically appropriate health care and other services. There are self-report and performance-based measures designed to assess physical functioning for the purposes of health research. With self-report measures, older adults report their perceived ability to perform a task, whereas performance-based measures directly record their performances. Researchers have examined the association between self-report and performance-based measures of physical function in aging populations, but findings suggest that self-report and performance-based measures are not strongly associated, likely due to various reporting biases and that they may not measure the same construct (5). Rather, self-report measures and performance-based measures may complement each other in providing comprehensive information about the physical function status of older adults (6–8). U.S. national normative data consistently reported higher prevalence of physical disabilities among minority older adults relative to non-Hispanic white (9,10). In addition, longitudinal studies of community-dwelling black and white older adults suggested that not only the racial disparities existed in baseline data, but black disadvantage in physical disabilities increased over time with age (11,12). A few regional studies also investigated the physical health status of Asian American older adults and found that Asian American older adults may exhibit poorer physical health than older adults in the general population; furthermore, there existed a high level of heterogeneity of physical health burden among different Asian American subcategories (13,14). Although reducing racial/ethnic disparities in physical disabilities remain a national priority of Health People 2020 program (15), progress toward this goal requires more systematic studies of overall physical function among all subpopulations of older adults. To our knowledge, relatively little is known regarding physical function status among U.S. Chinese older adults, one of the fastest growing aging populations in the country (16).Owing to obstacles in data collection, subgroup heterogeneity, and recruitment barriers, limited assessments exist of physical function among U.S. Chinese older adults (17). The lack of population-based epidemiological research that utilizes comprehensive measures of physical function in the U.S. Chinese population also makes it difficult to compare functional status across racial/ethnic groups. Furthermore, existing qualitative studies suggest that Chinese older adults often perceived their aging process accompanied by a sense of helplessness, and feeling of no control over the course of life and illnesses. The insecurity about physical function decline may be associated with placing less importance on health-seeking behaviors, delayed treatment, and worsened quality of life (17,18). Therefore, the purpose of this study was to expand our current understanding of physical function status of aging populations using both self-reported measures and performance-based measures. Specifically, using data drawn from a large population-based study of U.S. Chinese older adults, the current study aimed to: (i) assess physical function, utilizing both self-reported and performance-based measures, (ii) examine the association between self-reported and performance-based measures of physical function, and (iii) explore sociodemographic and health status correlates of physical function in Chinese older adults.