Biomedical subjects

Douglas A Wolf

Publications and source records attributed to Douglas A Wolf.

13 recordsLinked to original sources

PubMed2006

Improving knowledge about disability transitions by adding retrospective information to panel surveys. Population health metrics.

BACKGROUND: Panel data are often used to estimate key measures of public health, such as years lived with and without disability. Panel surveys commonly measure disability at intervals of one or two years, and occasionally more than two. It is likely that these intervals often include unreported changes in functional status. Unreported changes may bias estimates of disability transition probabilities, which are commonly used to estimate years lived with and without disability. Most surveys do not ask participants about periods with and without disability in the time since they last responded to the survey. We examined a way to improve the usefulness of panel surveys and our understanding of disability processes, by eliciting retrospective disability information. METHODS: Data were from the United States' National Long Term Care Survey. At each wave, this survey asks disabled respondents how long they have been disabled. We tested whether estimates of probabilities predicting changes in disability status can be improved by making use of this retrospective disability information. Methods included embedded Markov Chain analysis, microsimulation, and the Hausman specification test. RESULTS: Estimates based on data that include retrospective information are significantly different from those that use only the more limited information that is contemporaneous to the surveys. They are also more efficient. At age 65, all estimated probabilities for becoming disabled were higher when retrospective information was used, and all probabilities for remaining disabled were lower. Microsimulation revealed that using retrospective information increased the number of functional status transitions. For example, for women the mean number of transitions from nondisabled to disabled or dead was 52.7% greater when retrospective information was added to the analysis. CONCLUSION: Our results suggest that the value of future panel studies for estimating transitions in disability could be notably enhanced by adding a small number of questions asking respondents for details about their disabilities--and lack of disabilities--in the period since a preceding survey wave. Information provided by such questions could substantially improve both the measurement of disability histories and estimates of disability processes.

Journal Article↗

PubMed2006

Parent care and the stress process: findings from panel data.

OBJECTIVE: The purpose of this study was to test with panel data an extended model of the stress process recognizing the separate effects of a parent's need for care and an adult child's caring activities. METHODS: Using data from the 1996, 1998, and 2000 waves of the Health and Retirement Study, we estimated nonlinear mixed models of mental health outcomes. We assessed mental health for separate samples of 3,350 men and 3,659 women by using an 8-item scale of depressive symptoms. We also explored the sensitivity of results to alternative measures and model specifications. RESULT: We found that female, but not male, caregivers whose parents needed care exhibited adverse mental health consequences. However, we found that, generally, both male and female non-caregivers whose parents needed care were more likely to report symptoms of depression than were non-caregivers without disabled parents. Additional findings suggest that the stress process is still more complex among married couples. DISCUSSION: This study distinguishes the outcomes of parental care needs from those attributable to caregiving activities. Adverse psychological outcomes appear to be dispersed throughout the family. To focus narrowly on active caregivers is to underestimate the social burdens of disability at older ages.

Adult Children↗

PubMed2006

Promoting declines in the prevalence of late-life disability: comparisons of three potentially high-impact interventions.

Although the prevalence of late-life disability has been declining, how best to promote further reductions remains unclear. This article develops and then demonstrates an approach for comparing the effects of interventions on the prevalence of late-life disability. We review evidence for three potentially high-impact strategies: physical activity, depression screening and treatment, and fall prevention. Because of the large population at risk for falling, the demonstrated efficacy of multi-component interventions in preventing falls, and the strong links between falls and disability, we conclude that, in the short run, multi-component fall-prevention efforts would likely have a higher impact than either physical activity or depression screening and treatment. However, longer-term comparisons cannot be made based on the current literature and may differ from short-run conclusions, since increases in longevity may temper the influences of these interventions on prevalence. Additional research is needed to evaluate longer-term outcomes of interventions, including effects on length and quality of life.

Accidental Falls↗

PubMed2005

Reconsidering substitution in long-term care: when does assistive technology take the place of personal care?

OBJECTIVE: Assistive technology (AT) may improve quality of life and reduce dependence for older persons with disabilities. In this article, we examine tradeoffs between the use of AT and reliance on personal care, with attention to factors that may influence those relationships. METHODS: We jointly modeled hours of formal and informal care with use of AT in order to address the interdependence of these outcomes in ways not taken into account in previous studies. We analyzed a national sample of older persons with difficulty in activities of daily living drawn from Phase 2 of the 1994-1995 National Health Interview Survey (NHIS) Disability Supplement. RESULTS: Our findings show that the use of AT was associated with reductions in informal care hours, especially for those who were unmarried, better educated, or had better cognitive abilities, but appeared to supplement formal care services for these groups. Individuals with cognitive impairment were less likely than others to substitute AT with either type of personal care. DISCUSSION: These models raise the possibility that reductions of informal care hours may be accomplished with a combination of formal care and assistive devices, rather than from either alternative alone.

Activities of Daily Living↗

PubMed2005

Our "increasingly mobile society"? The curious persistence of a false belief.

PURPOSE: We call attention to the widespread belief that the United States is an "increasingly mobile society," despite the fact that overall mobility has generally declined since about 1950, and interstate mobility has generally not increased during the same period. We review and extend past research documenting these mobility trends. DESIGN AND METHODS: We describe population-level mobility for people of all ages as well as for several adult age groups, using published data from the U.S. Current Population Survey. We use simple regression methods to estimate the size and significance of mobility trends. RESULTS: Overall mobility rates have declined for individuals of all ages and among all age groups. The largest average annual declines occur for 20- to 29-year-olds, although the rate of decline for those aged 65 and older is also large. Interstate mobility has declined slightly or remained constant, except among adults between 45 and 64 years old. IMPLICATIONS: Although there may be good reasons to worry about the future of family care provided to elderly individuals, increased geographic mobility does not appear to be one of them. We speculate on reasons why the false belief persists.

Adult↗

PubMed2005

Perspectives on the recent decline in disability at older ages.

A decline has been found in the prevalence of disability among the older U.S. population during the 1980s and 1990s. One source of evidence for this decline is data from the National Long-Term Care Survey (NLTCS). This article investigates possible ambiguities in measuring disability using large-scale household surveys, illustrating the consequences of such problems with new analyses of NLTCS data. The reanalysis suggests a more gradual decline in disability than that found in prior research. The article also discusses three societal trends in areas other than health or functioning that might contribute to declines in disability levels: a reduced supply of informal care, changes in the technology of self-care, and changes in the definition and perception of both "ability" and "disability."

Aged↗

PubMed2004

Disability and home care dynamics among older unmarried Americans.

OBJECTIVES: We describe how paid and unpaid home care hours received by older unmarried Americans change in response to disability dynamics. We test whether responses to disability declines and improvements are symmetric; that is, we test whether reductions in care hours that are due to disability improvements are of similar magnitude to increases in care hours that are due to disability declines. METHODS: Using a national sample of older unmarried Americans, we examine changes in total hours, paid hours, and unpaid hours of care in response to declines and improvements in personal care (activities of daily living, or ADLs) and routine care (instrumental ADLs, or IADLs) disability. We model changes in the total hours of care received in the past month and jointly model changes in unpaid and paid hours, using Tobit models. RESULTS: Changes in the total hours of care received respond to both increases and decreases in the count of ADL limitations and appear close to symmetric. In contrast, responses to IADL disability dynamics appear to be far less symmetric: Although increases in the count of IADL limitations are met with substantial increases in the total hours of care, decreases are not met with correspondingly large declines in care. The same general pattern is found for unpaid and paid care, and for Medicaid-funded home care. DISCUSSION: Disability and care are not static constructs in old age. Older unmarried persons experience worsening, stabilizing, and recovery of function, and their care hours change accordingly. Evaluations of home care programs must be cognizant of such dynamic realities.

Activities of Daily Living↗

PubMed2004

Living arrangements among older people: an overview of trends in Europe and the USA.

This article compares the trends in living arrangements of older people in several European countries and in the United States. Trends and cross-country variability in several factors that could account for these cross-national differences, including marital status, fertility, labour force participation and attitudes, are also examined. In most countries the proportion of older people living alone increased substantially between 1970 and 1990. However the increase in living alone stabilised or even declined between 1990 and 2000 in most of the countries analysed indicating a possible reversal in the trend. Increases in proportions of older women who are married and reductions in the proportions childless may partially explain this. Considerable variability in both trends and levels of older people's living arrangements was seen especially between north-western and southern European countries. These variations mirrored contrasts in attitudes towards residential care and parent-child coresidence between the countries.

Adult↗

PubMed2003

Place characteristics and residential location choice among the retirement-age population.

OBJECTIVES: We investigate the association between an extensive set of location-specific factors and the propensity of retirement-age individuals to remain in, or relocate to, those locations. In particular we investigate whether state and local fiscal factors influence the migration decisions of retirees, and we study the relative importance of fiscal and other factors in these decisions. METHODS: We place decisions regarding whether to move and where to locate in a single discrete-choice framework. We estimate an individual-level location-choice model by using a combination of place-characteristics data and Census county-to-county migration data for the period 1985-1990. RESULTS: We find that levels of tax burdens and public services can affect location decisions. Of the fiscal variables, income taxes have the largest relative effects. However, other factors, including climate, economic conditions, and population characteristics, appear to play much larger roles in migration and location decisions. DISCUSSION: Although income tax reductions might influence the location decisions of recent retirees, whether or not the economic benefits associated with these population gains outweigh the accompanying revenue losses is an important area for further research. A more cost-effective strategy may be for states to focus on marketing their amenities rather than using fiscal policy to recruit retirees.

Aged↗

PubMed2003

Caregiver stress and noncaregiver stress: exploring the pathways of psychiatric morbidity.

PURPOSE: This study examines depressive symptoms among adult children of elderly parents; it views the parents' care needs and child's care activities as two separate stressors, different combinations of which may affect both caregiving and noncaregiving family members. DESIGN AND METHODS: A sample of 4,380 women and 3,965 men from the first wave of the Health and Retirement Study was analyzed by use of four alternative forms of multiple regression analysis. Using the Center for Epidemiological Studies Depression scale, respondents reported on their depressive symptoms, as well as on parental disability and care provided by themselves, their spouses, and siblings. RESULTS: Noncaregivers reporting severe parental disability were significantly more likely to experience depression symptoms. Evidence of increased manifestations of depression was not found among those caring for severely disabled relatives; nor was it found among those providing care in the absence of severe parental care needs. Having a caregiving sibling was associated with increased CES-D scores among noncaregivers. IMPLICATIONS: In the current literature, personal care needs of a close relative are named among significant disturbances in the lives of caregivers. By extending this approach to members of a family network regardless of caregiver status, this study allows us to distinguish the magnitude of negative outcomes of serious parental care needs while clarifying the impact uniquely attributable to caregiving activities.

Caregivers↗

PubMed2002

Functionally relevant thresholds of quadriceps femoris strength.

The purpose of this study was to identify quadriceps femoris strength thresholds below which performance on ambulatory tasks is compromised. A second purpose was to evaluate whether self-reported functioning matches evaluated performance of the activities. Subjects (N = 100; age 73 +/- 0.9 years) participated in isometric knee extension strength tests, performed three functional ambulatory tasks (chair rise, gait speed, and stair ascent and descent), and answered standard survey questions assessing physical function. Significant relationships were observed between functional performance and the ratio of isometric leg extension peak torque to body weight (STR/WT) for each activity (p <.0001). For each activity, thresholds of STR/WT between 3.0 and 3.5 N m/kg were observed, below which the likelihood for success was reduced. Thresholds were determined by calculating the value of STR/WT that minimized the classification error. Individuals with a STR/WT < 3.0 N m/kg are at a substantial risk for impaired function in chair rise, gait speed, and stair ascent and descent. Sensitivity and specificity of STR/WT as a predictor of functional success ranged from 76% to 81% and from 78% to 94%, respectively, depending on activity. This is of clinical significance, as the STR/WT thresholds can identify individuals with preclinical disability (beginning to have difficulty with ambulatory tasks) as opposed to those in whom an outright disability is observed. This may be useful for targeting individuals for strengthening interventions and developing specific intervention goals.

Aged↗

PubMed2002

Patterns of active life among older women: differences within and between groups.

This study examines the distribution of total, unimpaired, and impaired life for several groups of older women defined by race, education, and marital history. Using data from the 1984-1990 Longitudinal Study of Aging, we model transitions among functional statuses using discrete-time Markov chains, and use microsimulation to produce summary indices of active life. Remaining years of life and the proportion of remaining years with disability vary substantially, both within each group of women studied and between pairs of groups. Of all groups studied, never-married, more-educated white women live the longest, healthiest lives. Ever-married nonwhite women with low education have the shortest life expectancy, and experience the most disability. Our findings show that life expectancy is an incomplete indicator of the time women, in particular sub-groups, can expect to live with and without impairment. These findings highlight the heterogeneity of disability processes and life expectancy for older women.

Activities of Daily Living↗

PubMed2002

Child care subsidies and the employment of welfare recipients.

Changing patterns of maternal employment, coupled with stronger work requirements for welfare recipients, are increasing the demand for child care. For many families, the cost of child care creates a financial burden; for mothers with low incomes and those who are former welfare recipients, these costs may be an insurmountable barrier to employment or economic self-sufficiency. Despite increased public spending in this area, the receipt of any child care subsidy appears to be a relatively rare and uncertain event. In this study, we use data from a sample of low-income single mothers (current and recent welfare recipients in California) to estimate the probability of their receiving child care subsidies and the effect of this probability on labor market activity.

California↗