Evidence-Based Practice Centers
AHRQ awards 5-year contracts to institutions in the U.S. and Canada to serve as Evidence-based Practice Centers (EPCs). Several of the topics covered by these centers involve the health of older persons, with particular focus on the Medicare population. Examples of evidence reports produced by the centers that deal directly with the aging population include Osteoporosis in Postmenopausal Women and Cost-Effectiveness Analysis of Colorectal Cancer Screening and Surveillance Guidelines.29 A report on screening for dementia is forthcoming.
Broadening the Evidence Base for Evidence-Based Guidelines
This AHRQ-supported report outlines some major areas in which research is needed to define the appropriate use for specific screening tests, counseling interventions, immunizations, and chemoprophylaxis. This report focuses on identifying what the most reliable and effective ways are to measure and improve the delivery and quality of preventive care provided in the primary care setting.30
CDC and NIA
CDC and NIA have collaborated on a number of reports that utilized national data on the health and well-being of older Americans.
Aging Trends is a series of reports developed by the CDC's National Center for Health Statistics, with support from NIA, that highlight some of the most important health issues facing older Americans. These reports use multiple sources of data to monitor the health and well-being of the older populations. Each report identifies opportunities for prevention and further research, describes those most at risk, and identifies areas in which increased use of existing services and aids would be beneficial. Four reports have been completed to date, including Trends in Causes of Death Among the Elderly, Trends in Vision and Hearing Among Older Americans, The Oral Health of Older Americans, and The Changing Profile of Nursing Home Residents: 1985-1997.31
Trends in Health and Aging
The CDC's National Center for Health Statistics, with support from NIA, maintains a data warehouse and accompanying website (entitled Trends in Health and Aging). This website presents trends in health-related behaviors, health status, health care utilization, and the cost of care for the older U.S. population. Data are available for academic researchers and public users to search and download. Users have free access to a data dissemination tool to retrieve and display tabular information. CDC plans a significant expansion of the resources and data included in the warehouse on an ongoing basis.32
Longitudinal Studies of Aging (LSOA)
The Longitudinal Studies of Aging (LSOA) is a collaborative project of the CDC's National Center for Health Statistics and NIA. This study analyzes multiple cohorts of persons 70 years of age and older and is designed primarily to measure changes in health, functional status, living arrangements, and the health services utilization of two cohorts of Americans as they move into and through the oldest ages.
A Second Supplement on Aging followed the original LSOA in 1994. This supplement replicated the first study, roughly 10 years later, with a new cohort of persons 70 years of age and older. It was designed in part to provide the data necessary for analyzing changes in health and functioning among older Americans. The study used a nationally representative sample of 9,447 civilian non-institutionalized persons, and the data were collected through personal interviews in the household.
All waves of the LSOA include questionnaire items dealing with self-care practices and activities of daily living (ADL), with a focus on identifying barriers and restraints to normal levels of activity.
The four identified aims of this Second Supplement on Aging are as follows:
provide a replication of the first Study on Aging in order to determine whether there have been changes in the level of disability among older persons between 1984 and the mid-1990s. Availability of replicated health and functioning measures and their covariates collected on two distinct cohorts will enable researchers to evaluate whether the prevalence of disability or the factors associated with disability are different for the current cohort of women and men aged 70 years and over as compared to those of the cohort who were aged 70 years and over 10 years ago.
provide information on the causes and correlates of changes in health and functioning among older Americans, including background demographic characteristics, health behaviors and attitudes, preexisting illness, and social and environmental support.
provide information on the sequence and consequences of health events, including utilization of health care and services for assisted community living; on the physiological consequences of disability such as changes in social activities, living arrangements, social support, and use of community services; and on the deployment of assisted living strategies and the accessibility of technological and environmental adaptations.
serve as the baseline for the first national second-generation prospective study focusing on older Americans, the Second Longitudinal Study of Aging.33
NIA Demography of Aging Centers
The NIA has established 11 centers on the demography of aging. These centers have been charged with providing innovative and policy-relevant research on health, social factors, economics, and other issues that affect the U.S. older population. Research Highlights in the Economics and Demography of Aging is a series of reports prepared for NIA as a cooperative activity of the demography centers. Report titles include The Health and Retirement Study Part I--History and Overview; The Declining Disability of Older Americans; Socioeconomic Status, Health, and Longevity; Early Retirement in the United States; Social Security and Retirement Around the World; and Health Insurance and Retirement. In addition to these reports, the centers have produced numerous research reports and articles related to health and aging.34
We next briefly describe the major surveys conducted by the NIA's aging centers.
National Long Term Care (LTC) Survey
This longitudinal study, sponsored by NIA and ASPE focuses on the health and well-being of older Americans. It was first conducted in 1982, again in 1984, and has since been conducted every 5 years. The survey population is drawn from Medicare beneficiary enrollment files and is nationally representative of both community and institutional residents.
The survey's purpose is to provide nationally representative data on the prevalence and patterns of functional limitations, both physical and cognitive; longitudinal and cohort patterns of change in functional limitation and mortality over a 12-year period; medical conditions and recent medical problems; health care services used; the kind and amount of formal and informal services received by impaired individuals and how it is paid for; demographic and economic characteristics like age, race, sex, marital status, education, and income and assets; out-of-pocket expenditures for health care services and other sources of payment; and housing and neighborhood characteristics.35
In 1994, several items assessing health promotion and self-care activities were added to the LTC survey. The frequency and duration of physical activity and the perceived effect of physical activity on heart and breathing function were examined. Respondents also were asked about their history of regular exercise and participation in sports, as well as their perceived level of physical activity compared with that of their peers. Barriers to physical activity also were assessed in the 1994 instrument. Finally, a section on current nutrition and social activities, and five new items assessing current smoking and alcoholic beverage consumption were added to the 1994 LTC survey.
The Health and Retirement Study (HRS)
The Health and Retirement Study (HRS), conducted by the University of Michigan, surveys more than 22,000 Americans over the age of 50 every 2 years. The study focuses on physical and mental health, insurance coverage, financial status, family support systems, labor market status, and retirement planning. Its purpose is to provide data for researchers, policy analysts, and program planners who are making major policy decisions that affect retirement, health insurance, saving, and economic well-being.
The NIA first awarded the University of Michigan's Institute for Social Research a 5-year cooperative agreement in 1990 to plan and undertake a study that would contain a comprehensive source of data on retirement. The study utilized a national panel design and included an initial sample of 12,600 persons. The baseline survey was conducted in-home, with follow-ups conducted by telephone every second year, with proxy interviews after death. The stated objectives of HRS are to
- explain the antecedents and consequences of retirement;
- examine the relationship between health, income, and wealth over time;
- examine the life cycle patterns of wealth accumulation and consumption;
- monitor work disability;
- provide a rich source of interdisciplinary data, including linkages with administrative data; and
- examine how the mix and distribution of economic, family, and program resources affect key outcomes, including retirement, dissaving, health declines, and institutionalization.36
A section of the survey devoted to health status included items dealing with activities of daily living (ADL), current levels of physical activity, as well as current smoking and drinking practices. Questions also were asked about the use of secondary prevention measures, such as whether the respondent was following a special diet either to reduce blood pressure or to prevent complications from diabetes.
The fourth wave of data collection was completed in 1999, and the study is currently at the end of its second 5-year funding cycle. The University of Michigan has recently submitted a proposal to NIA to renew funding for three more waves of data collection.
Study of Assets and Health Dynamics Among the Oldest Old (AHEAD)
The Study of Assets and Health Dynamics among the Oldest Old (AHEAD) was designed to detail the joint dynamics among health (physical, cognitive, and functional), economic and family resources, and care arrangements. Wave I data collection for this national panel study was completed in 1994; Wave II was completed in 1996; and Wave III, which was fielded as a joint data collection activity with HRS, ended in 1999. Among the health promotion/disease prevention topics that were addressed by the survey were barriers to physical activity, and current smoking and drinking behaviors.
The overall objectives of this study are to:
- monitor transitions in physical, functional, and cognitive health in advanced old age;
- examine the relationship of late-life changes in physical and cognitive health to patterns of dissaving and income flows;
- relate changes in health to economic resources and intergenerational transfers; and
- examine how the mix and distribution of economic, family, and program resources affect key outcomes, including institutionalization, dissaving, and health declines.36
The Wisconsin Longitudinal Study (WLS)
The Wisconsin Longitudinal Study (WLS), supported in part by NIA, was designed to study the life course, intergenerational transfers and relationships, family functioning, physical and mental health and well-being, and morbidity and mortality from late adolescence through middle age. Items measured include social background, youthful aspirations, schooling, military service, family formation, labor market experiences, and social participation. Information about perceived general health status, smoking and alcoholic beverage consumption, and extent of self-care activities was also included.
This long-term study consists of a random sample of 10,317 men and women who graduated from Wisconsin high schools in 1957. Survey data were collected from the original respondents or their parents in 1957, 1964, 1975, and 1992, and from a selected sibling in 1977 and 1994. NIA is supporting a new wave of interviews with graduates, siblings, spouses, and widows during 2003-2004.
Because the WLS cohort was primarily born in 1939, it precedes the baby boom generation by about a decade. Therefore, this study was designed to provide an opportunity to assess early indications of trends and problems that will become important as the baby boom generation reaches old age. The study is unique in that it is the first large, longitudinal study of American adolescents, and thus provides the first opportunity to study the life course from late adolescence through the mid-fifties.37
Baltimore Longitudinal Study on Aging (BLSA)
The NIA's Baltimore Longitudinal Study on Aging (BLSA), begun in 1958, is America's longest-running scientific study of human aging. The study was designed to analyze what happens as people age and how to sort out changes due to aging from those due to disease or other causes. More than 1,200 men and women, ranging in age from the twenties to the nineties, have been involved to date as study volunteers.
Included in the many (nearly 100) data types and associated studies within the BLSA are several data files dealing with physical activity, attitudes toward physical activity, nutrient intake, and smoking history. For instance, at each visit, BLSA participants are asked to complete a physical activity questionnaire. The questionnaire asks them to estimate the amount of time they spend doing each of 100 activities.
The schedule and inventory entitled "Your Activities and Attitudes" is given to each participant to be filled out without supervision at the individuals' first visit and re-administered at every fourth visit. The inventory is composed of three parts: background information, including general information about the participant and his earlier life; an activity inventory; and an attitude inventory.
The activity inventory component of the questionnaire provides eleven sub-scores in such areas as leisure-time and religious activities, intimate personal contacts, security, and health status. The attitude inventory component deals with the personal aspects of adjustment. It contains eight groups of statements concerning health, friends, work, economic security, religion, and feelings of usefulness, happiness, and family.
A Physical Functioning Inventory (PFI) is included in the overall questionnaire to measure level of functioning with daily activities. It consists of 22 items, with each item followed by several probes, as appropriate. Each of 22 items describes a task commonly performed as part of daily functioning, such as driving, preparing meals, climbing stairs, bathing, and using the telephone. The probes establish the level of difficulty (if any) experienced in performing the task, and modifications made to enhance the performance of each task.
Since 1961, there has been an ongoing study of food habits of the men participating in the longitudinal study. Daily average intakes have been computed from a 7-day diet record, and additional calculations have been performed to obtain the percentage of total calories from fats, carbohydrates, and proteins; the polyunsaturated to saturated fatty acid ratio; simple and complex carbohydrate intakes; and the percentage of calories from saturated and unsaturated fatty acids.
Several important findings from this study have been reported in the literature, including the following:
Normal aging of the human heart and arteries is a risk factor for cardiovascular disease at older age.
Lifestyle and medications could help slow the decline in heart function of older people.
Cholesterol continues to be a risk factor for heart disease in elderly men.
Dementia and cognitive declines may be predicted as many as 20 years before symptoms are observed.
Short-term visual memory declines over time, but vocabulary increases until people are in their eighties.
Non-steroidal anti-inflammatory drugs such as ibuprofen may reduce the risk for Alzheimer's disease.
Older people cope more effectively with stress than young adults.
Self-reported happiness is more predictable from a person's disposition than from the special events he or she encounters.38
National Survey of Self Care and Aging (NSSCA)
The National Survey of Self Care and Aging is a longitudinal data set of community-based older adults. The sampling universe consists of all Medicare beneficiaries in the contiguous United States who were 65 years of age or older in 1989 and did not reside in nursing homes or domiciliary care facilities at the time of selection. Baseline in-person interviews were conducted during the fall and winter of 1990-1991 with 3,485 non-institutionalized adults aged 65 and older. Subjects were selected from the Medicare beneficiary files according to a stratified random sampling design. The unique aspects of this study include the large number of subjects in the oldest-old (85 and older) category and the large number of rural subjects. The initial in-person interviews obtained extensive information on functional status and self-care coping strategies related to functional status limitations. A telephone follow-up survey of subjects was conducted in 1993-1994.
Among the functional status and self-care activities examined at both time intervals was the presence and severity of difficulties in performing basic activities of daily living (ADLs), mobility activities of daily living (MADLs), and instrumental activities of daily living (IADLs); and behavioral and environmental adaptations made by older persons to mitigate actual or perceived functional difficulties resulting from disability. Self-care coping strategies included obtaining informal assistance from others; using equipment, clothing, or devices (such as telephones with large numbers); modifying behavior (such as avoiding stairs to prevent falls); and changing one's environment (such as moving to a residence with more services) in order to remain living in the community over time.39
SAMHSA Data Collection Activities
The SAMHSA Office of Applied Studies (OAS) collects and analyzes data on older populations and projects the need for substance abuse treatment among seniors through the year 2010. This project includes an in-depth review of the literature and consultation with federal and non-federal experts to better understand substance abuse among older persons, including how substance abuse changes as people age and the incidence and impact of comorbidities.
A significant focus of this project is to identify existing sources of data and potential measures to enable projections of substance abuse among older adults in the future. Of particular interest will be projections of substance abuse among the baby boom cohort (born between 1946 and 1964), which evidenced the highest historic rate of substance abuse. This cohort will begin turning 65 in 2011.
Currently, major sources of data (e.g., the National Household Survey of Drug Abuse, the National Longitudinal Alcohol Epidemiological Study, Veterans Administration patient data, and data from several surveys of the National Center for Health Statistics) are being analyzed for projections of future need. SAMHSA is considering expanding the National Household Survey on Drug Abuse and developing a module that pertains to older adults. Work on these activities is being shared with an interagency workgroup composed of representatives of SAMHSA's three Centers as well as NIA, CMS, NIMH, National Institute on Alcohol Abuse and Alcoholism, National Institute on Drug Abuse, AoA, the Department of Veterans Affairs, and other relevant agencies. A preliminary model is under development that defines the measures necessary to project substance abuse and misuse among older adults.24