Decomposition of disparities in life expectancy with applications to administrative health claims and registry data.

Research shows that geographic disparities in life expectancy between leading and lagging states are increasing over time while racial disparities between Black and White Americans have been going down. In the 65+ age strata morbidity is the most common cause of death, making differences in morbidity and associated adverse health-related outcomes between advantaged and disadvantaged groups an important aspect of disparities in life expectancy at age 65 (LE65). In this study, we used Pollard's decomposition to evaluate the disease-related contributions to disparities in LE65 for two types of data with distinctly differing structures: population/registry and administrative claims. To do so, we analyzed Pollard's integral, which is exact by construction, and developed exact analytic solutions for both types of data without the need for numerical integration. The solutions are broadly applicable and easily implemented. Applying these solutions, we found that the largest relative contributions to geographic disparities in LE65 were chronic lower respiratory diseases, circulatory diseases, and lung cancer; and, to racial disparities: arterial hypertension, diabetes mellitus, and cerebrovascular diseases. Overall, the increase in LE65 observed over 1998-2005 and 2010-2017 was primarily due to a reduction in the contributions of acute and chronic ischemic diseases; this was partially offset by increased contributions of diseases of the nervous system including dementia and Alzheimer's disease.

The quadratic hazard model for analyzing longitudinal data on aging, health, and the life span.

A better understanding of processes and mechanisms linking human aging with changes in health status and survival requires methods capable of analyzing new data that take into account knowledge about these processes accumulated in the field. In this paper, we describe an approach to analyses of longitudinal data based on the use of stochastic process models of human aging, health, and longevity which allows for incorporating state of the art advances in aging research into the model structure. In particular, the model incorporates the notions of resistance to stresses, adaptive capacity, and "optimal" (normal) physiological states. To capture the effects of exposure to persistent external disturbances, the notions of allostatic adaptation and allostatic load are introduced. These notions facilitate the description and explanation of deviations of individuals' physiological indices from their normal states, which increase the chances of disease development and death. The model provides a convenient conceptual framework for comprehensive systemic analyses of aging-related changes in humans using longitudinal data and linking these changes with genotyping profiles, morbidity, and mortality risks. The model is used for developing new statistical methods for analyzing longitudinal data on aging, health, and longevity.

How much do junior staff know about common legal situations in paediatrics?

BACKGROUND: Recent high-profile medico-legal cases such as the death of Victoria Climbie and the subsequent Laming report have highlighted widespread deficiencies in child protection practice. Junior doctors are the frontline staff regularly facing issues with potentially major legal implications, including child protection, Gillick competence, consent, and professional responsibility/accountability. It is therefore important for them to be aware and understand the Children Act, common medico-legal principles and practices, particularly in the current, increasingly litigious climate. AIMS: (1) To determine junior medical staff's knowledge of legal issues involved in child protection and common basic legal situations, and (2) to assess whether experience and training improved this knowledge. METHODS: A standardized structured interview was developed exploring common issues with important legal implications for paediatric practice. It focused on: legal issues in child protection, the Children Act, awareness of the General Medical Council (GMC), principles of professional responsibility/accountability, the Bolam principle for good medical practice and Gillick competence. Basic demographic data were recorded. We attempted to contact all 180 paediatric junior medical staff in Wales by telephone. RESULTS: Interviews were conducted with 119/180 (66%) doctors: 46/56 specialist registrars (SpRs; 82%) and 73/124 senior house officers (SHOs; 59%). SpRs scored a median of 6.5 correct responses from a possible of 12 (range 3-11), compared with a median of 5 (range 1-11) by the SHOs (P < 0.0001; Mann-Whitney test). A third of SHOs and a fifth of SpRs were unaware that the GMC was the organization responsible for good medical practice in the UK. Similarly, a fifth of all juniors were ignorant of the legal age for consent. Approximately two-thirds of the SHOs and half of the SpRs were ignorant that the police and social services have the legal power to protect the child in child protection cases. Alarmingly, none of the SHOs and only 11% of the SpRs were aware of the Bolam principle. SpRs scored significantly higher on topics of Gillick competence, legal right to see medical notes, consent, Children Act, burden of proof in civil and criminal court, and on Bolam principle. They also had received training more frequently than SHOs, which, when combined with their greater experience, probably explains these statistically significant differences. CONCLUSION: Few junior staff have adequate knowledge of the basic legal principles and practice as they relate to children. Widespread deficiencies concerning the understanding of the Children Act and child protection powers exist.

Product liability forecasting for asbestos-related personal injury claims: a multidisciplinary approach.

This paper focuses on three aspects of forecasting models for asbestos-related disease/injuries relating to the Manville asbestos case: (1) The structure of forecasting models for asbestos-related personal injuries. (2) The epidemiologic evidence supporting the selected model structure and the constraints on the modeling assumptions imposed by that evidence. (3) The range of uncertainty associated with projections based on these forecasting models and issues relating to decision making under uncertainty.

Predicting 10-year care requirements for older people with suspected Alzheimer's disease.

OBJECTIVE: To describe the types and costs of care received for 10 years after the identification of an older person with suspected Alzheimer's disease (AD) by using data from 3254 patients with suspected AD who participated in the National Long Term Care Survey (NLTCS). METHODS: By using a Markov model derived using grade of membership techniques, the following were determined: survival probabilities at 10 years; years of survival during the 10 years; years in institutions; years with two or more impairments in basic activities of daily living; hours of paid and informal care while the older person lived in the community; and costs of paid community, institutional, and medical care. RESULTS: Greater degrees of cognitive impairment present when AD was identified were associated with reduced predicted probability of surviving 10 years, increased predicted number of years spent in institutions, increased hours of care required while affected individuals remained in the community, and increased costs of paid community, institutional, and medical care. Substantial differences between men and women were seen: severity-adjusted 10-year costs were almost two times higher for women with AD than for men ($75,000 compared with $44,000); according to sensitivity analysis, average 10-year costs might be as high as $109,000 for women and $67,000 for men. CONCLUSIONS: AD imposes a substantial burden on older persons. Interventions that slow the progression of the disease may therefore affect community survival as well as healthcare costs.

The dynamics of dimensions of age-related disability 1982 to 1994 in the U.S. elderly population.

Declines in chronic disability were observed in the National Long Term Care Survey (NLTCS) 1982 to 1994. We analyzed the 1982, 1984, 1989, and 1994 NLTCS to identify the dimensions of chronic disability from multivariate analyses of a rich battery of measures of the ability (or inability) to perform specific activities. Changes over time in the prevalence of individual disability dimensions can be tracked to evaluate the rate of age-related losses of specific functions, 1982-1994. Seven dimensions described changes in the age dependence of 27 activities of daily living, instrumental activities of daily living, and physical performance measures in community and institutional resident elderly individuals over the 12 year period. Adjusted for age, the healthiest dimension with the best physical function experienced the largest increase in prevalence (3.3%) implying a decline in age-related disability. Disability declines were correlated with reductions in select health conditions (e.g., dementia and circulatory disease) over the study period.

Education-specific estimates of life expectancy and age-specific disability in the U.S. elderly population: 1982 to 1991.

The authors used mortality data for 1982 to 1991 linked to survey records from the 1982, 1984, and 1989 National Long Term Care Surveys to calculate gender differences over age in mortality and functional status for high (8 or more years of schooling) and low (less than 8 years of schooling) education subgroups. Males and females with high education maintained better functioning at later ages than those with low education. The authors also found that mortality was higher, after conditioning on disability, in both the male and female low-education than the male and female high-education groups. The size of the education effect on both disability and mortality was large, for example, about 7.6 years difference in female life expectancy at age 65; a roughly 2-year difference for males.

Chronic disability trends in elderly United States populations: 1982-1994.

Statistically significant declines in chronic disability prevalence rates were observed in the elderly United States population between the 1982 and 1989 National Long Term Care Surveys (NLTCS). The 1994 NLTCS was used to investigate whether disability rate declines continued to 1994. The 1982, 1984, 1989, and 1994 NLTCS employ the same sample design and instrumentation so that trends in disability can be estimated with minimal sampling and measurement bias. Age (5-year categories from 65 to >95)-specific rates were calculated for the 1982 NLTCS and applied to United States Census Bureau estimates of the 1994 population to calculate chronic disability prevalence rates adjusted for aging in the United States population aged > 65. The 1982 age standardized rates were compared with 1994 NLTCS estimates. The prevalence of disability estimated for 1994 (21.3%) was 3.6% lower than the 1982 age standardized rate (24.9%)-a highly significant reduction (t = -8.5; P << 0.0001). Of the 3.6 percentage point decline in prevalence, 1.7% occurred in the 5 years between 1989 and 1994-compared with the 1.9% decline in the 7 years between 1982 and 1989. Both declines are significant. Because of the shorter time period, the per year decline in disability prevalence from 1989 to 1994 was greater than that from 1982 to 1989. Given the higher acute and long-term care service needs of the disabled elderly population, Medicare, Medicaid, and private health expenditures may be dramatically lower than if declines had not occurred.

Changes in the age dependence of mortality and disability: cohort and other determinants.

Though the general trend in the United States has been toward increasing life expectancy both at birth and at age 65, the temporal rate of change in life expectancy since 1900 has been variable and often restricted to specific population groups. There have been periods during which the age- and gender-specific risks of particular causes of death have either increased or decreased. These periods partly reflect the persistent effects of population health factors on specific birth cohorts. It is important to understand the ebbs and flows of cause-specific mortality rates because general life expectancy trends are the product of interactions of multiple dynamic period and cohort factors. Consequently, we first review factors potentially affecting cohort health back to 1880 and explore how that history might affect the current and future cohort mortality risks of major chronic diseases. We then examine how those factors affect the age-specific linkage of disability and mortality in three sets of birth cohorts assessed using the 1982, 1984, and 1989 National Long Term Care Surveys and Medicare mortality data collected from 1982 to 1991. We find large changes in both mortality and disability in those cohorts, providing insights into what changes might have occurred and into what future changes might be expected.

Longevity in the united states: age and sex-specific evidence on life span limits from mortality patterns 1960-1990.

Determining the biological limits to human longevity is more difficult than for most other species because humans are long-lived. Consequently, mortality data, such as from the U.S. vital statistics system, which have been available for a long time (relative to most epidemiological studies) and have large numbers of cases, including deaths reported to advanced ages, are important in studying human longevity-though care must be exercised in dealing with error in age reporting. Furthermore, it is unlikely that free-living humans can realize as much of their biological endowment for longevity as animals living in a highly controlled experimental environment. We examined changes, 1960 to 1990, in U.S. White male and female extinct cohort life tables and age at death distributions to (a) examine evidence for the effects of a biological life span limit in current U.S. mortality patterns and (b) produce lower bound estimates of that limit.

Changes in health, mortality, and disability and their impact on long-term care needs.

The need for long-term care is driven both by the growth of the elderly population and changes in the age relations of morbidity, disability, and mortality. Data show these relations changed in the U.S. elderly population from 1982 to 1989. Chronic disability prevalence declined between the 1982 and 1989 U.S. National Long Term Care Surveys. Among those impaired, many persons using personal assistance to meet their needs shifted to the use of assisted housing and special equipment. The relation of these trends to other changes--such as the increasing educational level of the elderly population--is examined to estimate how future changes in disability and morbidity may affect the demand for long-term care. Disabilities at specific times as well as their transition rates were examined to determine how long individuals need long-term care. The analyses suggest that, while the amount of long-term care services needed will increase rapidly, the types and amounts of services used by the U.S. elderly population will undergo significant change.

Sex differences in human mortality and aging at late ages: the effect of mortality selection and state dynamics.

Models of gender differences in human mortality and aging depend on assumptions about temporal rates of physiological change. Simple models like the Gompertz fail to describe the mortality of either males or females at late ages. This suggests a need for biologically more detailed models to represent the age dependency of human mortality as well as gender differences in that age dependence. By modeling the sex-specific interaction of time-varying covariates with multiple dimensions of mortality selection, one can more accurately describe the age dependence of mortality and more complex physiological aging patterns. The multivariate model of aging changes is used to describe gender differences using data from (a) a longitudinal study of physiological changes and mortality and (b) a nationally representative longitudinal survey of changes in function and mortality.

Changes in morbidity and chronic disability in the U.S. elderly population: evidence from the 1982, 1984, and 1989 National Long Term Care Surveys.

We examined changes in the reported prevalence of 16 medical conditions in the U.S. population age 65 and above using data from the 1982, 1984, and 1989 National Long Term Care Surveys. Changes in those disease prevalence rates were examined both as observed, and after standardizing for changes in the age, sex, and disability distributions in the U.S. elderly population between 1982 and 1989. We found significant declines in the net prevalence of the 16 medical conditions between 1982 and 1989. Significant changes were found in different disability, age, and gender groups and after standardizing for declines in disability in addition to age and sex. The declines in morbidity reported between 1982 and 1989 are consistent with the declines reported in the 1982 and 1989 National Long Term Care Surveys in the age and sex standardized prevalence of chronic disability and institutionalization.

The effects of health histories on stochastic process models of aging and mortality.

A model of human health history and aging, based on a multivariate stochastic process with both continuous diffusion and discrete jump components, is presented. Discrete changes generate non-Gaussian diffusion with time varying continuous state distributions. An approach to calculating transition rates in dynamically heterogeneous populations, which generalizes the conditional averaging of hazard rates done in "fixed frailty" population models, is presented to describe health processes with multiple jumps. Conditional semi-invariants are used to approximate the conditional p.d.f. of the unobserved health history components. This is useful in analyzing the age dependence of mortality and health changes at advanced age (e.g., 95+) where homeostatic controls weaken, and physiological dynamics and survival manifest nonlinear behavior.

Time-varying covariates in models of human mortality and aging: multidimensional generalizations of the Gompertz.

Models of mortality and aging depend on assumptions about physiological change even if they are not made explicit. Standard models, like the Gompertz, often fail to describe mortality at extreme ages, suggesting a need for biologically more detailed and flexible models. One solution is to model the interaction of time-varying covariates with mortality to better describe the age dependence of mortality, test hypotheses about the relation of physiological change and mortality, and use longitudinal data to generalize assumptions about physiological change. This model is applied to (a) a 34-year follow-up of risk factors and mortality and (b) a 9.5-year follow-up of function and mortality from longitudinal surveys of the U.S. elderly population.

Home health and skilled nursing facility use: 1982-90.

In this article, analyses are made of home health and skilled nursing facility (SNF) use for the period 1982-90 using Medicare records linked to data on community and institutional residents from the National Long-Term Care Surveys (NLTCSs) of 1982, 1984, and 1989. The combined survey and administrative data analyses are performed to ascertain how the chronic health and functional characteristics of community and institutional residents using Medicare-reimbursed services changed during the period. During this period, changes had been made in the Medicare system that affected the use of services for persons with specific health and functional problems.

Forecasts of active life expectancy: policy and fiscal implications.

Age-related changes in functional status can be summarized by active life expectancy (ALE) measures. ALE is useful in assessing efforts to improve function and in determining a population's service needs. ALE disaggregates total life expectancy (TLE) into components representing degree and type of impairment. We illustrate the calculation of two ALE measures and their relations to health inputs and service use. First, scores are calculated from 27 measures of function for persons 65 and over, as reported in the National Long Term Care Survey (NLTCS). The scores are then used to calculate the two ALE measures. Results are compared to ALE calculated from the 1982, 1984, and 1989 NLTCS.

Use of Medicare services before and after introduction of the prospective payment system.

OBJECTIVE: The case mix-adjusted pattern of use of health care services, especially posthospital care, is compared before and after the introduction of Medicare's Prospective Payment System (PPS). DATA SOURCES: The 1982 and 1984 National Long Term Care Surveys (NLTCS) linked to Medicare administrative records 1982-1986 provide health and health service use data for 12-month periods before and after the introduction of PPS. STUDY DESIGN: Case-mix differences between pre- and post-periods are controlled by using the Grade of Membership model to identify health groups from the NLTCS data. Differences in timing (e.g., hospital length of stay) were controlled using life table models estimated for each health group, that is, service use patterns pre- and post-PPS are compared within groups. PRINCIPAL FINDINGS: Hospital LOS and admission rates declined post-PPS. Changes in the timing and location of death occurred but, overall, mortality did not increase. Changes in post-acute care service use by elderly, chronically disabled Medicare beneficiaries were observed: home health service use increased overall and among the unmarried disabled population. CONCLUSIONS: PPS did not adversely affect quality of care as reflected in mortality or in hospital readmissions. Moreover, the differential use of post-acute care, and changes in hospital LOS by health group, indicate that the system responded, specific to marital status and age, to the severity of needs of chronically disabled persons.

Estimates of change in chronic disability and institutional incidence and prevalence rates in the U.S. elderly population from the 1982, 1984, and 1989 National Long Term Care Survey.

The U.S. elderly (65+) and oldest-old (85+) populations are growing rapidly which, combined with their high per capita acute and long-term care needs, will increase total U.S. health care needs. Also important in determining needs is how health and function change as mortality declines in the elderly population. Recent increases in adult life expectancy have been due to declines in stroke and heart disease mortality. There is controversy, however, about how those declines relate to the health and function of survivors. We examined changes in the prevalence and incidence of chronic disability using the 1982, 1984, and 1989 National Long Term Care Surveys. The total prevalence of U.S. chronically disabled community-dwelling and institutionalized elderly populations declined from 1984 to 1989, overall, for each of three age strata and after mortality adjustment. These changes varied over level of disability. Factors contributing to these changes, including measurement, are reviewed.