Modeling and Forecasting Health Expectancy: Theoretical Framework and Application

Life expectancy continues to grow in most Western countries; however, a major remaining question is whether longer life expectancy will be associated with more or fewer life years spent with poor health. Therefore, complementing forecasts of life expectancy with forecasts of health expectancies is useful. To forecast health expectancy, an extension of the stochastic extrapolative models developed for forecasting total life expectancy could be applied, but instead of projecting total mortality and using regular life tables, one could project transition probabilities between health states simultaneously and use multistate life table methods. In this article, we present a theoretical framework for a multistate life table model in which the transition probabilities depend on age and calendar time. The goal of our study is to describe a model that projects transition probabilities by the Lee-Carter method, and to illustrate how it can be used to forecast future health expectancy with prediction intervals around the estimates. We applied the method to data on the Dutch population aged 55 and older, and projected transition probabilities until 2030 to obtain forecasts of life expectancy, disability-free life expectancy, and probability of compression of disability.     

Survival of related individuals: An extension of some fundamental results of heterogeneity analysis

Many ideas in the analysis of heterogeneous mortality are based on the relationship between individual and observed hazard rates. This connection is established with the help of conditional averaging procedure: The observed risk of death at age x is calculated among those who survive this age. The analogy of this result for bivariate survival model with correlated individual hazards is derived. In the case of correlated frailty model the parametric specification of the mean, variance and correlation coefficient of the bivariate frailty distribution among survivors is obtained. The relationship between local association measure and the characteristics of the bivariate frailty distribution among survivors is established.     

Dynamics of Mixed Coalitions Under Social Cohesion Constraints

ABSTRACT

Parameters for the birth and death diffusion life table model subject to downward jumps randomly occurring at a constant rate are estimated. The jump magnitudes have a beta distribution with support [0, l_x ], where l_x is the total number of survivors prior to the jump. The estimation method is maximum likelihood. The Cramer–Rao Lower bound and the asymptotic distribution for the MLE are derived. The model is applied to the U.S. men′s population from 1900 to 1999.     

A semi‐Markovian approach to using event history data in multiregional demography

As a first step towards infusing event‐history analysis into multiregional demography, this paper introduces a semi‐Markovian framework and outlines its salient features as differentiated from a pure Markovian framework. Specifically, what differentiates the former from the latter is an explicit consideration of duration‐dependence in migrating from one region to another. This duration‐dependence is one of the complexities involved in using event‐history data in multiregional demography. The use of event‐history data lends itself easily to defining basic probabilities involved in a semi‐Markovian framework directly on sample paths of individuals. The underlying concepts of a semi‐Markov process in the special case of time‐homogeneity or age‐independence of transition probabilities are given in a coherent and concise form. Illustrations of empirical applications to the event‐history data on migration as provided by the Korean National Migration Survey conducted in 1983, and of distinct features of the semi‐Markovian analysis through a parametrization of the basic probabilities are also given in this paper.     

Obtaining multistate life table distributions for highly refined subpopulations from cross-sectional data: A bayesian extension of sullivan’s method

Multistate life table methods are often used to estimate the proportion of remaining life that individuals can expect to spend in various states, such as healthy and unhealthy states. Sullivan’s method is commonly used when panels containing data on transitions are unavailable and true multistate tables cannot be generated. Sullivan’s method requires only cross-sectional mortality data and cross-sectional data indicating prevalence in states of interest. Such data often come from sample surveys, which are widely available. Although the data requirements for Sullivan’s method are minimal, the method is limited in its ability to produce estimates for subpopulations because of limited disaggregation of data in cross-sectional mortality files and small cell sizes in aggregated survey data. In this article, we develop, test, and demonstrate a method that adapts Sullivan’s approach to allow the inclusion of covariates in producing interval estimates of state expectancies for any desired subpopulation that can be specified in the cross-sectional prevalence data. The method involves a three-step process: (1) using Gibbs sampling to sample parameters from a bivariate regression model; (2) using ecological inference for producing transition probability matrices from the Gibbs samples; (3) using standard multistate calculations to convert the transition probability matrices into multistate life tables.     

The dependence of marriage migrations in Japan on personal factors and ecological variables

Marriage is an important migration‐inducing life‐cycle event. This paper uses a nested logit model to explain the interprefectural migration behaviors at marriage by personal factors and prefectural attributes, based on the micro data of the 1986 national migration survey of Japan. Before marriage, each person is considered a potential migrant making a two‐level decision: (1) to stay or depart and (2) to choose a destination. The main findings are as follows.

Destination choice propensities were affected by such attributes of potential destination as income (+), employment growth (+), distance (‐), contiguity (+), and linguistic similarity (+). Non‐natives appeared to be less sensitive to the attraction of economic opportunities. Personal factors were less important than prefectural attributes in affecting destination choice propensities.

Departure propensities were affected by not only such attributes of origin prefecture as income (‐), employment growth (‐), and population density (+) but also the “inclusive variable”; (+), which reflected the attractiveness of the rest of the system. Despite being strongly emphasized in the literature, sibling status was less important than gender, nativity and education in affecting departure propensities. Personal factors were much more important than prefectural attributes in determining the departure propensities.     

Modeling Transition Rates Using Panel Current-Status Data: How Serious is the Bias?

Studies of disability dynamics and active life expectancy often rely on transition rates or probabilities that are estimated using panel survey data in which respondents report on current health or functional status. If respondents are contacted at intervals of one or two years, then relatively short periods of disability or recovery between surveys may be missed. Much published research that uses such data assumes that there are no unrecorded transitions, applying event-history techniques to estimate transition rates. In recent years, a different approach based on embedded Markov chains has received growing use. We assessed the performance of both approaches, using as a criterion their ability to reproduce the parameters of a “true” model based on panel data collected at one-month intervals. Neither of the widely used approaches performs particularly well, and neither is uniformly superior to the other.     

A model of numbers of births in three countries,with persistent forty‐year cycles

A non‐linear model of fertility is described, which was derived from data for more than a century from England and Wales, New Zealand, and the U.S.A. The demographic transition is modelled with a logistic function, and age‐specific fertility rates are estimated using lognormal distributions. The stepwise inclusion of a partner availability estimate in the model showed that it accounts for twenty‐nine percent of otherwise unexplained variance. Projected future births stabilise in sustained or limit cycles with periods a little longer than 40 years, and amplitudes at least 7% of the mean. The necessary conditions for cycle persistence are outlined on a graph of maximum and minimum fertility parameters.     

Existential aspects as an inevitable part of salutogenesis in maternity care – A discussion paper

BackgroundPoor mental health is considered a major health challenge globally, not least for young people, who will form families within forthcoming years. Research related to childbirth and parenthood transition has focused on how to promote good mental health by preventing mental illness.AimWe discuss how a salutogenetic approach to mental health in parenthood transition is beneficial, and specifically how the component of meaningfulness in Sense of Coherence (SoC), could be investigated to optimize good mental health during parenthood transition.DiscussionIn more recent understandings of meaningfulness, ideas from existential philosophy and psychology have been included. We discuss how, from an existential psychological perspective, open and explorative questioning of life conditions and dilemmas may help to regain one’s footing and get in touch with one’s driving force – meaningfulness. Such questioning implies that someone, a professional or a friend, actively and relationally helps explore existential aspects of life.ConclusionWe believe that investigating and asking research questions pointing at optimizing a salutogenetic perspective, specifically focusing on the component of meaningfulness and its embedded existential aspects of life, could lead to new knowledge on how to promote good mental health in maternity care.     

A relational technique for estimating the age‐specific mortality pattern from grouped data

This paper presents a new technique of expanding an abridged life table. This technique is a non‐parametric one, which relates the probabilities of dying of the abridged table to those of a standard complete table. In order to evaluate the accuracy of the new technique we use it, as well as two other techniques, for expanding empirical abridged data sets. According to the results of our calculations the new method proves very efficient in producing complete life tables from grouped data, in many cases producing more accurate results than the other two methods in spite of its simplicity.     

Midwife experiences of providing continuity of carer: A qualitative systematic review

ProblemContinuity of carer models present positives and challenges for midwives working in them, and are difficult to sustain.BackgroundResearch shows midwifery continuity of carer improves perinatal outcomes and experiences, and is considered the optimal model of care.AimTo synthesise existing research on midwives’ experiences of providing continuity of carer and generate further understanding of what sustains them in practice.MethodsProtocol for the review was developed using PRISMA guidelines and registered with PROSPERO. 22 studies were included with original themes and findings extracted using JBI tools and synthesised using meta-ethnographic techniques. GRADE CERQual assessment of review findings showed high confidence.FindingsMidwives identified working in continuity of carer models as both fulfilling and challenging. Professional autonomy and ability to develop meaningful relationships were the most commonly cited positives, while lack of work life balance and conflict with the wider maternity team were the main challenges. 15 studies identified strategies employed by midwives which sustained them in practice.DiscussionMidwife experiences of providing continuity are impacted by personal and professional factors. Of paramount importance to sustainability of the model is the support of the wider organisation, and their alignment with principles of person-centred, relational care.ConclusionRelational models of care are desired by midwives, service users and are recommended in policy. Relational models of care must be responsive to midwives needs as well as birthing people, and therefore need to be designed and managed by those working in them and supported by the whole organisation to be sustainable.     

Feedback Spreading Control Applied to Immunotherapy

The method of maximum likelihood is used to estimate parameterized transition probabilities of a non-homogeneous Markov chain model of movements between the health states disability-free, disabled, and death. A complication is that individuals are observed at irregular intervals, implying that particular attention must be paid to computational issues. Numerical results including estimated health expectancies and their standard errors are given for data from the Longitudinal Study on Aging (LSOA) of 1984-86-88-90 (Kovar et al. 1992). The weak ergodicity of prevalence on the non-absorbing states is established and supports the hypothesis of the compression of morbidity.     

A behavioral two‐sex marriage model

In this paper we propose a particular marriage model, i.e., a model for the number of marriages for each age combination as a function of the vectors of the number of single men and women in each age group. The model is based on Dagsvik (2000) where it is demonstrated that a general type of matching behavior imply, under specific assumptions about the distribution of the preferences of the women and men, a convenient expression for the corresponding marriage model.

Data from the Norwegian Population Register for nine years are applied to estimate the model. We subsequently test the hypothesis that, apart from a random “noise”; component, the age‐specific parameters of the model change over time according to a common trend. We find that the hypothesis is not rejected by our data.     

Estimation of life expectancy — cohort life table

Life tables are traditionally built with linear assumptions for the survival curve. Here, considering that survivors can remain at the end of the observation period, the author shows that non linear modeling is more appropriate. With data on cervix uteri cancer, e0 ≈ 12.5 years with standard error ≈ 2.8 years with infinite time horizon, but e0 ≈ 6.0 years with standard error ≈ 0.1 year in interval with finite time horizon [0, 12 years]. The average hazard function is introduced to estimate the life expectancy, and the actuarial estimate of the hazard function is showed to under‐estimate the true hazard values under the exponential distribution. Finally, a sensitivity analysis of the probabilities of death on the estimation of life expectancy completes the study.     

The multistate stable population model with immigration

This paper outlines the discrete‐time and continuous‐time formulations of the stable population model with immigration, showing their commonality. It then illustrates how the model can be extended to include multiple interacting populations, and goes on to consider a multistate version of reproductive value that further illuminates the evolutionary dynamics of an “open”; model of multistate population growth and redistribution. Attention is restricted to results arising from a fertility regime that is below replacement level.     

Population growth with variable family size

The Sharpe‐Lotka continuous time deterministic model of population growth is developed to take account of some possible forms of mother‐daughter fertility association, characterised here by a bivariable measure, A. This leads to a linear double integral equation for which, subject to certain conditions, a finite time solution can be found by Laplace transform methods and thus also model specific results relating the intergenerational fertility effect to the long term population growth rate and magnitude are established. The quantitative implications of the theory are illustrated by a consideration of a general bilinear form of A and in this context numerical results illustrating the finite time growth and also the long term distribution of fertility levels in the stable female population are obtained. In particular, it is shown that different fertility specific subpopulations can coexist indefinitely.     

Combining forward and backward mortality estimation

Demographers often form estimates by combining information from two data sources—a challenging problem when one or both data sources are incomplete. A classic example entails the construction of death probabilities, which requires death counts for the subpopulations under study and corresponding base population estimates. Approaches typically entail ‘back projection', as in Wrigley and Schofield's seminal analysis of historical English data, or ‘inverse’ or ‘forward projection’ as used by Lee in his important reanalysis of that work, both published in the 1980s. Our paper shows how forward and backward approaches can be optimally combined, using a generalized method of moments (GMM) framework. We apply the method to the estimation of death probabilities for relatively small subpopulations within the United States (men born 1930–39 by state of birth by birth cohort by race), combining data from vital statistics records and census samples.     

A qualitative study of innovations implemented to improve transition of care from maternity to child and family health (CFH) services in Australia

BackgroundThe transition of care (ToC) from maternity services, particularly from midwifery care to child and family health (CFH) nursing services, is a critical time in the support of women as they transition into early parenting. However significant issues in service provision exist, particularly meeting the needs of women with social and emotional health risk factors. These include insufficient resources, poor communication and information transfer, limited interface between private and public health systems and tension around role boundaries. In response some services are implementing strategies to improve the transition of care from maternity to CFH services.AimThis paper describes a range of innovations developed to improve transition of care between maternity and child and family health services and identifies the characteristics common to all innovations.MethodsData reported were collected in phase three of a mixed methods study investigating the feasibility of implementing a national approach to child and family health services in Australia (CHoRUS study). Data were collected from 33 professionals including midwives, child and family health nurses, allied health staff and managers, at seven sites across four Australian states. Data were analysed thematically, guided by Braun and Clarke's six-step process of thematic analysis.FindingsThe range of innovations implemented included those which addressed; information sharing, the efficient use of funding and resources, development of new roles to improve co-ordination of care, the co-location of services and working together. Four of the seven sites implemented innovations that specifically targeted families with additional needs. Successful implementation was dependent on the preliminary work undertaken which required professionals and/or organisations to work collaboratively.ConclusionImproving the transition of care requires co-ordination and collaboration to ensure families are adequately supported. Collaboration between professionals and services facilitated innovative practice and was core to successful change.