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D
isability—the gap between an individual’s capabilities and the demands of the environment—is highly prevalent among older adults and increases substantially with age. According to the U.S. Census Bureau, approximately 42% of older adults—or more than 15 million people age 65 and older—experience some level of disability in their daily lives. About one in 10 older adults has severe disability that requires them to acquire assistance with self-care. Disability has implications not only for the quality of life of individuals facing functional loss, but also for family members who most often provide informal care. Economic consequences include lost productivity and strains on the nation’s medical and long-term care bill. The number of older Americans with disability is expected to swell over the next 25 years as the baby boom generation enters old age. Accordingly, disability prevention is a major public health issue for the 21st century.
The good news is that, according to scientists who study population aging, the chances of having disability in late life are declining. Why this is the case has been a great mystery. But if the prevalence of disability continues to decline, this trend could have major consequences for the nation, with potentially a greater number of older adults able to work and fewer requiring the assistance of family members and long-term-care providers.
For the last 10 years I have been collaborating with colleagues across the country to understand the nature of these trends and what they imply for the future. Drawing upon both epidemiologic and demographic tools, we have resolved discrepancies across studies, tracked the decline into the 21st century, identified disturbing disparities and explored reasons for the trend.
This topic first emerged more than 25 years ago as researchers were trying to understand the societal implications of declining death rates in late life. Did longer life mean worsening health? Or did falling death rates mean the period of disability might be compressed into fewer years? Early evidence was mixed, with some studies reporting large declines in disability and others concluding that there was no clear ongoing trend.
Over the last decade, more than a dozen studies focusing on late-life disability trends have appeared in the medical and public health literature. With funding from the National Institute on Aging, my colleagues Linda Martin of the Institute of Medicine and Robert Schoeni of the University of Michigan and I reviewed these findings in an article appearing in the Journal of the American Medical Association. Highlighting methodological considerations, we found that studies consistently showed substantial declines in instrumental activities related to independent living—tasks such as shopping, managing money and doing laundry—but that there remained disagreement with respect to more severe limitations in personal care activities such as bathing, dressing and eating.
To resolve the remaining inconsistencies, we organized a technical working group composed of national experts on disability measurement and trends. The 12-person panel prepared estimates from five different national surveys using identical methodologies. We found that during the mid- and late-1990s, there were consistent declines in personal care limitations, but these trends were less pronounced than those for instrumental activities. Moreover, the panel identified another important and related trend: an increase in reports of the use of equipment to carry out personal care activities.
| Prevalence of Late-Life Disability |
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| According to the National Health Interview Survey, the prevalence of late-life disability has declined from 23% in 1982 to less than 16% in 2004. |
In a current study funded by the National Institute on Aging, my colleagues and I have tracked these trends into the 21st century. Analyzing responses to the National Center for Health Statistics’ National Health Interview Survey, we have found that the disability among older Americans was just under 16% in 2004, compared to 23% in 1982 (see figure). Results recently published in the American Journal of Public Health also suggest a new and disturbing trend: disparities by education and income, which favor those with higher socioeconomic status, have generally widened in the last 20 years. The growing gap can be attributed to the fact that declines were not as large among the nation’s less advantaged elders.
With respect to causes of the overall decline, we have investigated a number of potential explanations in a series of published studies. Our research thus far suggests that the decline in disability is likely to be the result of a combination of factors and not any single underlying cause. We have found, for example, that the elderly as a group are much better educated today than in the mid-1980s. Such a change accounts for a substantial portion of the decline although the mechanism is not clear since education may influence disability through a number of channels. There is also evidence that some chronic conditions are less debilitating now than in previous decades, even as the prevalence of many of those conditions has increased in the older population. Cognitive functioning also appears to be improving and there have been declines in the percentage of older adults reporting vision difficulties. And older adults are increasingly turning to assistive technologies to increase, maintain or improve their functional capabilities. For example, in a recently published analysis in the Gerontologist, we found that declines between 1992 and 2001 in the number of older people getting help with personal care activities could be attributed to shifts toward assistive technology, which helped to offset increases resulting from population growth and population aging.
Participation in society to the fullest extent possible by people with disabilities, whether young or old, is a key public health goal. Translating this aim into reality will undoubtedly require further unraveling of the causes and consequences of the decline in late-life disability. Only by understanding past trends will the nation be able to undertake efforts to plan for—and ultimately prevent—the burden of disability among its oldest members.
Vicki A. Freedman, PhD, is a professor in the Department of Health Systems and Policy, UMDNJ-School of Public Health. Dr. Freedman has published extensively on the topics of population aging, disability and long-term care. She is currently principal investigator on an NIA-funded study of late-life health trends. A member of the Institute of Medicine’s Committee on Disability in America, Dr. Freedman received her PhD in epidemiology from Yale University. She joined the UMDNJ faculty in 2005.
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