Modeling and Forecasting Health Expectancy: Theoretical Framework and Application

Research Note: A Novel Sullivan Method Projection Framework With Application to Long COVID

Originally developed for estimating healthy life expectancy, the traditional Sullivan method continues to be a popular tool for obtaining point-in-time estimates of the population impacts of a wide range of health and social conditions. However, except in rare data-intensive cases, the method is subject to stringent stationarity assumptions, which often do not align with real-world conditions and restrict its resulting estimates and applications. In this research note, we present an expansion of the original method to apply within a population projection framework. The Sullivan method projection framework produces estimates that offer new insights about future trends in population health and social arrangements under various demographic and epidemiologic scenarios, such as the percentage of life years that population members can expect to spend with a condition of interest in a time interval under different assumptions. We demonstrate the utility of this framework using the case of long COVID, illustrating both its operation and potential to reveal insights about emergent population health challenges under various theoretically informed scenarios. The traditional Sullivan method provides a summary measure of the present, while its incorporation into a projection framework enables preparation for a variety of potential futures.

Racial, Ethnic, Nativity, and Educational Disparities in Cognitive Impairment and Activity Limitations in the United States, 1998-2016

Despite extensive research on cognitive impairment and limitations in basic activities of daily living, no study has investigated the burden of their co-occurrence (co-impairment). Using the Health and Retirement Study data and incidence-based multistate models, we study the population burden of co-impairment using three key indicators: mean age at onset, lifetime risk, and health expectancy. We examine patterns by gender, race, ethnicity, nativity, education, and their interactions for U.S. residents aged 50-100. Furthermore, we analyze what fractions of racial, ethnic, and nativity disparities in co-impairment are attributable to inequalities in educational attainment. Results reveal that an estimated 56% of women and 41% of men aged 50 will experience co-impairment in their remaining life expectancy. Men experience an earlier onset of co-impairment than women (74 vs. 77 years), and women live longer in co-impairment than men (3.4 vs. 1.9 years). Individuals who are Black, Latinx, and lower educated, especially those experiencing intersecting disadvantages, have substantially higher lifetime risk of co-impairment, earlier co-impairment onset, and longer life in co-impairment than their counterparts. Up to 75% of racial, ethnic, and nativity disparity is attributable to inequality in educational attainment. This study provides novel insights into the burden of co-impairment and offers evidence of dramatic disparities in the older U.S. population.

Impact of access to childhood health services on healthy life expectancy of the older population

Background

Life course theory provides new perspectives on the impact of early experiences on health in old age, where unfortunate childhood experiences can alter an individual's health trajectory. This study aims to calculate the healthy life expectancy of the older population in China under different childhood experiences, and to explore the influence of childhood medical and health services on the health level of older adults.

Methods

Differences in healthy life expectancy of the older population under different childhood experiences were analyzed using the multi-state life table method to calculate the healthy life expectancy by sex and place of birth, based on the cohort data of Chinese Longitudinal Healthy Longevity Survey (CLHLS) from 2008 to 2018.

Results

The probability of the transition risk from health to non-health gradually increased with age, while the probability of the transition risk from non-health to health decreased with age; In both urban and rural areas, on the probability of the transition risk from health to non-health, the older adults who were able to receive timely medical and health services in childhood were lower than those who failed to receive medical services in time (Z = -5.833, P < 0.05), but the probability of the transition risk from non-health to health was the opposite (Z = -5.334, P < 0.05); The probability of the transition risk from health to death is also higher in older adults who were unable to receive timely medical care in childhood (Z = -5.88, P < 0.05); The healthy life expectancy and its proportion in the remaining life expectancy of older people who received medical and health services in time during childhood were significantly higher than those of their peers (Z = -5.88, P < 0.05).

Conclusions

The lack of medical services in childhood has a negative effect on the health of older adults. The healthy life expectancy and its proportion of remaining life expectancy were higher for rural older adults than for urban older adults under the same health care conditions in childhood; the health benefits of good access to health care environment or conditions in childhood were greater for rural older females.

Projections of healthy working life expectancy in England to the year 2035

UK state pension age is rising in response to life expectancy gains but population health and job opportunities may not be sufficient to achieve extended working lives^1-3. This study aimed to estimate future trends in healthy working life expectancy (HWLE) from age 50 to 75 for men and women in England. Using the 'intercensal' health expectancy approach, annual period HWLE from 1996 to 2014 was estimated using cross-sectional Health Survey for England data and mortality statistics^4-7. HWLE projections until the year 2035 were estimated from Lee-Carter forecasts of transition rates⁸. Projections of life expectancy from age 50 showed gains averaging 10.7 weeks (0.21 years) and 6.4 weeks (0.12 years) per calendar year between 2015 and 2035 for men and women respectively. HWLE has been extending in England but gains are projected to slow to an average of 1 week per year for men (0.02 years) and 2.8 weeks (0.05 years) per year for women between 2015 and 2035. Modest projected HWLE gains and the widening gap between HWLE and life expectancy from age 50 suggest that working lives are not extending in line with policy goals. Further research should identify factors that increase healthy working life.

Management of respiratory tract infections in young children-A qualitative study of primary care providers' perspectives

Respiratory tract infections in young children are the most common cause of general practice visits in Australia. Despite the availability of clinical practice guidelines, the treatment and management of respiratory tract infections in young children is inconsistent. The aim of the study was to explore the management of respiratory tract infections in young children from a multi-disciplinary perspective using across-sectional qualitative research design based on the theoretical domains framework and the Capability, Opportunity and Motivation-B model. In-depth interviews were conducted with 30 primary care providers to explore their knowledge, views and management of respiratory tract infections in young children. Interviews focused on symptomatic management, over-the-counter medications and antibiotic use, and data were thematically analysed. Our findings showed that factors such as primary care providers’ time constraints, parental anxiety, general practitioners’ perception of what parents want, perceived parental pressure, and fear of losing patients were some of the reasons why primary care providers did not always adhere to guideline recommendations. Primary care providers also provided conflicting advice to parents concerning over-the-counter medications and when children should resume normal activities. Overall, this study showed that complex interactions involving emotional and psychological factors influenced the decision making process of primary care providers’ management of respiratory tract infections in young children. A team care approach with consistent advice, and improved communication between primary care providers and parents is vital to overcome some of these barriers and improve guideline adherence. The findings of this research will inform the development of interventions to better manage respiratory tract infections in young children.

The emotions and psychology of both parents and clinicians influence how respiratory tract infections (RTIs) are managed in young children. Researchers in Australia, led by Ruby Biezen from Monash University, interviewed 30 primary care clinicians about their views on how to care for children with RTIs, such as the common cold. The interviews focused on symptomatic management, over-the-counter medications and antibiotic use. Despite the availability of best-practice guidelines, clinicians did not always follow the recommendations owing to factors such as time constraints, parental anxiety, perceived parental pressure, and fear of losing patients. These are some of the reasons why clinicians sometimes advise or prescribe unnecessary medications. The authors suggest that a team approach involving multiple healthcare professionals who deliver consistent advice could improve guideline adherence.

Future healthy life expectancy among older adults in the US: a forecast based on cohort smoking and obesity history

BACKGROUND

In the past three decades, the elderly population in the United States experienced increase in life expectancy (LE) and disability-free life expectancy (LE(ND)), but decrease in life expectancy with disability (LE(D)). Smoking and obesity are two major risk factors that had negative impacts on these trends. While smoking prevalence continues to decline in recent decades, obesity prevalence has been growing and is currently at a high level. This study aims to forecast the healthy life expectancy for older adults aged 55 to 85 in the US from 2011 to 2040, in relation to their smoking and obesity history.

METHODS

First, population-level mortality data from the Human Mortality Database (HMD) and individual-level disability data from the US National Health Interview Survey (NHIS) were used to estimate the transition rates between different health states from 1982 to 2010, using a multi-state life table (MSLT) model. Second, the estimated transition rates were fitted and projected up to 2040, using a modified Lee-Carter model that incorporates cohort smoking and obesity history from NHIS.

RESULTS

Mortality and morbidity for both sexes will continue to decline in the next decades. Relative to 2010, men are expected to have 3.2 years gain in LE(ND) and 0.8 years loss in LE(D). For women, there will be 1.8 years gain in LE(ND) and 0.8 years loss in LE(D). By 2040, men and women are expected to spend respectively 80 % and 75 % of their remaining life expectancy between 55 and 85 disability-free.

CONCLUSIONS

Smoking and obesity have independent negative impacts on both the survival and disability of the US older population in the coming decades, and are responsible for the present and future gender disparity in mortality and morbidity. Overall, the US older population is expected to enjoy sustained health improvements and compression of disability, largely due to decline in smoking.

Genome-Wide Estimates of Heritability for Social Demographic Outcomes

An increasing number of studies that are widely used in the demographic research community have collected genome-wide data from their respondents. It is therefore important that demographers have a proper understanding of some of the methodological tools needed to analyze such data. This article details the underlying methodology behind one of the most common techniques for analyzing genome-wide data, genome-wide complex trait analysis (GCTA). GCTA models provide heritability estimates for health, health behaviors, or indicators of attainment using data from unrelated persons. Our goal was to describe this model, highlight the utility of the model for biodemographic research, and demonstrate the performance of this approach under modifications to the underlying assumptions. The first set of modifications involved changing the nature of the genetic data used to compute genetic similarities between individuals (the genetic relationship matrix). We then explored the sensitivity of the model to heteroscedastic errors. In general, GCTA estimates are found to be robust to the modifications proposed here, but we also highlight potential limitations of GCTA estimates.

Did the health of the Dutch population improve between 2001 and 2008? Investigating age- and gender-specific trends in quality of life

Although many countries' populations have experienced increasing life expectancy in recent decades, quality of life (QoL) trends in the general population have yet to be investigated. This paper investigates whether QoL changed for the general Dutch population over the period 2001-2008. A beta regression model was employed to address specific features of the QoL distribution (i.e., boundedness, skewness, and heteroskedasticity), as well non-linear age and time trends. Quality-adjusted life expectancy (QALE) was calculated by combining model estimates of mean QoL with mortality rates provided by Statistics Netherlands. Changes in QALE were decomposed into those changes caused by QoL changes and those caused by mortality-rate changes. The results revealed a significant increase in QoL over 2001-2008 for both genders and most ages. For example, QALE for a man/woman aged 20 was found to have increased by 2.3/1.9 healthy years, of which 0.6/0.8 was due to QoL improvements.