National Population Growth Rate, Its Components, and Subnational Contributions: A Research Note.

A population's current growth rate is determined jointly by changes in fertility, mortality, and migration. This overall growth rate is also the average of age-specific growth rates, which can be decomposed into the result of historical changes in fertility, mortality, and migration. However, doing so requires more than 100 years of historical data, meaning that such analyses are possible only in a select few populations. In this research note, we propose an adapted version of the variable-r model to measure contributions to the population growth rate for countries with shorter demographic series. In addition, we extend this model to explore the contribution of subnational changes to the national population growth rate. Our results demonstrate that the age-specific growth rates obtained from short historical series, say 25 years, closely match those of the longer series. These abbreviated age-specific growth rates closely resemble the growth rate at birth of their respective cohorts, which is the major determinant of population growth, except at older ages where mortality becomes the main explanatory element. Exploring subnational populations, we find considerable heterogeneity in the age profile of the components of growth and find that the most populous regions tend to have an outsized impact on national-level growth.

Decomposition of Differentials in Health Expectancies From Multistate Life Tables: A Research Note.

Multistate modeling is a commonly used method to compute healthy life expectancy. However, there is currently no analytical method to decompose the components of differentials in summary measures calculated from multistate models. In this research note, we propose a derivative-based method to decompose the differentials in population-based health expectancies estimated via a multistate model into two main components: the proportion resulting from differences in initial health structure and the proportion resulting from differences in health transitions. We illustrate the method using data on activities of daily living from the U.S. Health and Retirement Study to decompose the sex differential in disability-free life expectancy (HLE) among older Americans. Our results suggest that the sex gap in HLE results primarily from differences in transition rates between disability states rather than from the initial health distribution of female and male populations. The methods introduced here will enable researchers, including those working in fields other than health, to decompose the relative contribution of initial population structure and transition probabilities to differences in state-specific life expectancies from multistate models.

A growing divide: Trends in social inequalities in healthy longevity in Australia, 2001-20.

This study examines two decades of change in social inequalities in life and health expectancy among older adults in Australia, one of the few countries that escaped an economic recession during the global financial crisis. We compare adults aged 45+ across three measures of individual socio-economic position-education, occupation, and household wealth-and use multistate life tables to estimate total life expectancy (TLE) and life expectancy free of limiting long-term illness (LLTI-free LE) based on 20 waves of the Household, Income and Labour Dynamics in Australia Survey (2001-20). Our findings highlight substantial social disparities in both TLE and LLTI-free LE in Australia. Grouping individuals by household wealth shows striking differentials in LLTI-free LE. We observe widening social disparities in healthy longevity over time by all three measures of socio-economic position. This diverging trend in healthy longevity is troubling against the backdrop of widening income and wealth inequalities in Australia.

Changes in Life Expectancy and Disability-Free Life Expectancy in Successive Birth Cohorts of Older Cancer Survivors: A Longitudinal Modeling Analysis of the US Health and Retirement Study.

The population of older cancer survivors in the United States is rapidly growing. However, little is currently known about how the health of older cancer survivors has changed over time and across successive birth cohorts. Using data from the US Health and Retirement Study, we parameterized a demographic microsimulation model to compare partial cohort life expectancy (LE) and disability-free LE for US men and women without cancer and with prevalent and incident cancer diagnoses for 4 successive 10-year birth cohorts, born 1918-1927 to 1948-1957. Disability was defined as being disabled in ≥1 activity of daily living. These cohorts had midpoint ages of 55-64, 65-74, and 75-84 years during the periods 1998-2008 (the "early" period) and 2008-2018 (the "later" period). Across all cohorts and periods, those with incident cancer had the lowest LE, followed by those with prevalent cancer and cancer-free individuals. We observed declines in partial LE and an expansion of life spent disabled among more recent birth cohorts of prevalent-cancer survivors. Our findings suggest that advances in treatments that prolong life for individual cancer patients may have led to population-level declines in conditional LE and disability-free LE across successive cohorts of older cancer survivors.

Expansion, Compression, Neither, Both? Divergent Patterns in Healthy, Disability-Free, and Morbidity-Free Life Expectancy Across U.S. Birth Cohorts, 1998-2016.

This article explores how patterns of health, morbidity, and disability have changed across successive generations of older adults in the United States. Using a novel method for comparing state-specific partial life expectancies-that is, total life expectancy (LE), and health expectancies (HEs) in different health states, bounded between two ages-I explore changes in healthy life expectancy across successive birth cohorts of the U.S. population. Results show that little compression of disability is occurring across cohorts, LE with chronic morbidities has expanded considerably, and self-rated health is improving across cohorts, but only at ages 70+. These findings suggest that successive cohorts in the U.S. population may be on divergent paths in terms of late-life health and well-being. Exploring heterogeneity in these patterns, I find that less educated individuals have substantially lower partial LE and disability-free LE than those with more schooling, and that disability-free life is declining among those with less than a high school diploma. Differences in HEs are pervasive across racial and ethnic groups, and both disabled LE and unhealthy LE are expanding in some disadvantaged subgroups. The continued increases in partial LE with morbidities across successive cohorts, and the broad stagnation of disability-free and healthy LE, present a broad view of a U.S. population in which successive generations are not living healthier lives.

The Components of Change in Population Growth Rates.

The demographic balance equation relates the population growth rate with crude rates of fertility, mortality, and net migration. All these rates refer to changes occurring between two time points, say, t and t + h. However, this fundamental balance equation overlooks the contribution of historical fertility, mortality, and migration in explaining these population counts. Because of this, the balance equation only partially explains a change in growth rate between time t and t + h as it does not include the contribution of historical population trends in shaping the population at time t. The overall population growth rate can also be expressed as the weighted average of age-specific growth rates. In this article, we develop a method to decompose the historical drivers of current population growth by recursively employing the variable-r method on the population's average age-specific growth rates. We illustrate our method by identifying the unique contributions of survival progress, migration change, and fertility decline for current population growth in Denmark, England and Wales, France, and the United States. Our results show that survival progress is mainly having an effect on population growth at older ages, although accounting for indirect historical effects illuminates additional contributions at younger ages. Migration is particularly important in Denmark and England and Wales. Finally, we find that across all populations studied, historical fertility decline plays the largest role in shaping recent reductions in population growth rates.

Life Course Socioeconomic Status and Healthy Longevity in China.

In 2020, China's population aged 60 or older exceeded 264 million, representing 25% of the global population in that age-group. Older adults in China experienced periods of dramatic political and social unrest in early life, as well as economic transformations leading to drastic improvements in living standards during adulthood and older age. However, the implications of life course socioeconomic status (SES) trajectories for healthy longevity in later life have not been systematically studied in China. We utilize data from the China Health and Retirement Longitudinal Study (CHARLS) to comprehensively investigate how early-life conditions and adult SES combine to influence healthy longevity in later life. We find that both childhood and adulthood SES are associated with late-life health. The largest disparities in life expectancy (LE) and disability-free LE are found between those with persistently low SES throughout life and those with consistently high SES. At age 45, the gap in total LE between the most advantaged and least advantaged groups is six years for men and five years for women. Despite China's major policy changes prioritizing equity in income and health care in recent decades, our findings suggest that dramatic health inequalities among older adults remain. Our findings extend the literature on the effect of socioeconomic patterns across the life course on gradients in later-life health and highlight continuing disparities in healthy longevity among older adults in China.

Developing and evaluating a frailty index for older South Africans-findings from the HAALSI study.

BACKGROUND: despite rapid population ageing, few studies have investigated frailty in older people in sub-Saharan Africa. We tested a cumulative deficit frailty index in a population of older people from rural South Africa. METHODS: analysis of cross-sectional data from the Health and Ageing in Africa: Longitudinal Studies of an INDEPTH Community (HAALSI) study. We used self-reported diagnoses, symptoms, activities of daily living, objective physiological indices and blood tests to calculate a 32-variable cumulative deficit frailty index. We fitted Cox proportional hazards models to test associations between frailty category and all-cause mortality. We tested the discriminant ability of the frailty index to predict one-year mortality alone and in addition to age and sex. RESULTS: in total 3,989 participants were included in the analysis, mean age 61 years (standard deviation 13); 2,175 (54.5%) were women. The median frailty index was 0.13 (interquartile range 0.09-0.19); Using population-specific cutoffs, 557 (14.0%) had moderate frailty and 263 (6.6%) had severe frailty. All-cause mortality risk was related to frailty severity independent of age and sex (hazard ratio per 0.01 increase in frailty index: 1.06 [95% confidence interval 1.04-1.07]). The frailty index alone showed moderate discrimination for one-year mortality: c-statistic 0.68-0.76; combining the frailty index with age and sex improved performance (c-statistic 0.77-0.81). CONCLUSION: frailty measured by cumulative deficits is common and predicts mortality in a rural population of older South Africans. The number of measures needed may limit utility in resource-poor settings.

Are China's oldest-old living longer with less disability? A longitudinal modeling analysis of birth cohorts born 10 years apart.

BACKGROUND: China has transitioned from being one of the fastest-growing populations to among the most rapidly aging countries worldwide. In particular, the population of oldest-old individuals, those aged 80+, is projected to quadruple by 2050. The oldest-old represent a uniquely important group-they have high demand for personal assistance and the highest healthcare costs of any age group. Understanding trends in disability and longevity among the oldest-old-that is, whether successive generations are living longer and with less disability-is of great importance for policy and planning purposes. METHODS: We utilized data from successive birth cohorts (n = 20,520) of the Chinese oldest-old born 10 years apart (the earlier cohort was interviewed in 1998 and the later cohort in 2008). Disability was defined as needing personal assistance in performing one or more of five essential activities (bathing, transferring, dressing, eating, and toileting) or being incontinent. Participants were followed for age-specific disability transitions and mortality (in 2000 and 2002 for the earlier cohort and 2011 and 2014 for the later cohort), which were then used to generate microsimulation-based multistate life tables to estimate partial life expectancy (LE) and disability-free LE (DFLE), stratified by sex and age groups (octogenarians, nonagenarians, and centenarians). We additionally explored sociodemographic heterogeneity in LE and DFLE by urban/rural residence and educational attainment. RESULTS: More recently born Chinese octogenarians (born 1919-1928) had a longer partial LE between ages 80 and 89 than octogenarians born 1909-1918, and octogenarian women experienced an increase in partial DFLE of 0.32 years (P = 0.004) across the two birth cohorts. Although no increases in partial LE were observed among nonagenarians or centenarians, partial DFLE increased across birth cohorts, with a gain of 0.41 years (P < 0.001) among nonagenarians and 0.07 years (P = 0.050) among centenarians. Subgroup analyses revealed that gains in partial LE and DFLE primarily occurred among the urban resident population. CONCLUSIONS: Successive generations of China's oldest-old are living with less disability as a whole, and LE is expanding among octogenarians. However, we found a widening urban-rural disparity in longevity and disability, highlighting the need to improve policies to alleviate health inequality throughout the population.

Tracking progress in mean longevity: The Lagged Cohort Life Expectancy (LCLE) approach.

Cohort life expectancy is an important but rarely used indicator of mean longevity. In this paper, we show that there are specific advantages in lagging this indicator in time by its own value, an approach termed Lagged Cohort Life Expectancy (LCLE). We discuss the usefulness of LCLE as an indicator for tracking progress in mean longevity and introduce a new interpretation of LCLE as a reference age separating 'early' deaths from 'late' deaths, or, equivalently, as the age above which individuals in a population can be considered 'above-average' survivors. Using data from 15 countries in the Human Mortality Database, we show that current LCLE can be estimated with a relatively high degree of certainty, at least in these low-mortality populations. Results shed new light on levels and trends in mean longevity in these populations.

Cognition, Health, and Well-Being in a Rural Sub-Saharan African Population.

Cognitive health is an important dimension of well-being in older ages, but few studies have investigated the demography of cognitive health in sub-Saharan Africa's (SSA) growing population of mature adults (= persons age 45+). We use data from the Malawi Longitudinal Study of Families and Health (MLSFH) to document the age and gender patterns of cognitive health, the contextual and life-course correlates of poor cognitive health, and the understudied linkages between cognitive and physical/mental well-being. Surprisingly, the age-pattern of decline in cognitive health is broadly similar to that observed in the U.S. We also find that women have substantially worse cognitive health than men, and experience a steeper age-gradient in cognitive ability. Strong social ties and exposure to socially complex environments are associated with higher cognitive health, as is higher socioeconomic status. Poor cognitive health is associated with adverse social and economic well-being outcomes such as less nutrition intake, lower income, and reduced work efforts even in this subsistence agriculture context. Lower levels of cognitive health are also strongly associated with increased levels of depression and anxiety, and are associated with worse physical health measured through both self-reports and physical performance. Our findings suggest that cognition plays a key-but understudied-role in shaping late-life well-being in low-income populations.

The Demography of Mental Health Among Mature Adults in a Low-Income, High-HIV-Prevalence Context.

Very few studies have investigated mental health in sub-Saharan Africa (SSA). Using data from Malawi, this article provides a first picture of the demography of depression and anxiety (DA) among mature adults (aged 45 or older) in a low-income country with high HIV prevalence. DA are more frequent among women than men, and individuals affected by one are often affected by the other. DA are associated with adverse outcomes, such as poorer nutrition intake and reduced work efforts. DA also increase substantially with age, and mature adults can expect to spend a substantial fraction of their remaining lifetime-for instance, 52 % for a 55-year-old woman-affected by DA. The positive age gradients of DA are not due to cohort effects, and they are in sharp contrast to the age pattern of mental health that has been shown in high-income contexts, where older individuals often experience lower levels of DA. Although socioeconomic and risk- or uncertainty-related stressors are strongly associated with DA, they do not explain the positive age gradients and gender gap in DA. Stressors related to physical health, however, do. Hence, our analyses suggest that the general decline of physical health with age is the key driver of the rise of DA with age in this low-income SSA context.

Prevalence and correlates of frailty in an older rural African population: findings from the HAALSI cohort study.

BACKGROUND: Frailty is a key predictor of death and dependency, yet little is known about frailty in sub-Saharan Africa despite rapid population ageing. We describe the prevalence and correlates of phenotypic frailty using data from the Health and Aging in Africa: Longitudinal Studies of an INDEPTH Community cohort. METHODS: We analysed data from rural South Africans aged 40 and over. We used low grip strength, slow gait speed, low body mass index, and combinations of self-reported exhaustion, decline in health, low physical activity and high self-reported sedentariness to derive nine variants of a phenotypic frailty score. Each frailty category was compared with self-reported health, subjective wellbeing, impairment in activities of daily living and the presence of multimorbidity. Cox regression analyses were used to compare subsequent all-cause mortality for non-frail (score 0), pre-frail (score 1-2) and frail participants (score 3+). RESULTS: Five thousand fifty nine individuals (mean age 61.7 years, 2714 female) were included in the analyses. The nine frailty score variants yielded a range of frailty prevalences (5.4% to 13.2%). For all variants, rates were higher in women than in men, and rose steeply with age. Frailty was associated with worse subjective wellbeing, and worse self-reported health. Both prefrailty and frailty were associated with a higher risk of death during a mean 17 month follow up for all score variants (hazard ratios 1.29 to 2.41 for pre-frail vs non-frail; hazard ratios 2.65 to 8.91 for frail vs non-frail). CONCLUSIONS: Phenotypic frailty could be measured in this older South African population, and was associated with worse health, wellbeing and earlier death.

The population-level impact of public-sector antiretroviral therapy rollout on adult mortality in rural Malawi.

BACKGROUND: Recent evidence from health and demographic surveillance sites (HDSS) has shown that increasing access to antiretroviral therapy (ART) is reducing mortality rates in sub-Saharan Africa (SSA). However, due to limited vital statistics registration in many of the countries most affected by the HIV/AIDS epidemic, there is limited evidence of the magnitude of ART's effect outside of specific HDSS sites. This paper leverages longitudinal household/family roster data from the Malawi Longitudinal Survey of Families and Health (MLSFH) to estimate the effect of ART availability in public clinics on population-level mortality based on a geographically dispersed sample of individuals in rural Malawi. OBJECTIVE: We seek to provide evidence on the population-level magnitude of the ART-associated mortality decline in rural Malawi and confirm that this population is experiencing similar declines in mortality as those seen in HDSS sites. METHODS: We analyze longitudinal household/family-roster data from four waves of the MLSFH to estimate mortality change after the introduction of ART to study areas. We analyze life expectancy using the Kaplan-Meier estimator and examine how the mortality hazard changed over time by individual characteristics with Cox regression. RESULTS: In the four years following rollout of ART, life expectancy at age 15 increased by 3.1 years (95% CI 1.1, 5.1), and median length of life rose by over ten years. CONTRIBUTION: Our observations show that the increased availability of ART resulted in a substantial and sustained reversal of mortality trends in SSA and assuage concerns that the post-ART reversals in mortality are not occurring at the same magnitude outside of specific HDSSs.

Inequalities in Mortality in the Asia-Pacific: A Cross-National Comparison of Socioeconomic Gradients.

OBJECTIVES: Social inequalities in mortality are poorly studied in much of the Asia-Pacific. Using data from harmonized nationally representative longitudinal health and aging surveys our study systematically assesses mortality disparities across 3 standardized measures of socioeconomic status in 7 Asia-Pacific countries. METHODS: We used data from multiple waves of 7 representative sample surveys: the Health, Income and Labour Dynamics in Australia survey, China Health and Retirement Longitudinal Study, the Indonesian Family Life Survey, the New Zealand Health, Work and Retirement survey, the Korean Longitudinal Study on Ageing and the Health, Aging and Retirement in Thailand survey, and the Japanese Study of Aging and Retirement. We use Cox proportional hazards modeling to examine how the hazard of mortality differs across domains of social stratification including educational attainment, wealth, and occupational status across countries. RESULTS: We found consistent and pervasive gradients in mortality risk in the high-income countries by all available measures of social stratification. In contrast, patterns of inequality in adult mortality in middle-income and recently transitioned high-income countries investigated varied depending on the measure of social stratification, with strong gradients by wealth but mixed gradients by education. DISCUSSION: Analyzing social gradients in mortality in the Asia-Pacific shows that inequalities, especially wealth-based inequalities, in later-life health are present across the region, and that the magnitude of social gradients in mortality is overall larger in high-income countries as compared to middle-income countries.

Frailty progression in adults aged 40 years and older in rural Burkina Faso: a longitudinal, population-based study.

BACKGROUND: Little is known about ageing and frailty progression in low-income settings. We aimed to describe frailty changes over time in individuals living in rural Burkina Faso and to assess which sociodemographic, disability, and multimorbidity factors are associated with frailty progression and mortality. METHODS: This longitudinal, population-based study was conducted at the Nouna Health and Demographic Surveillance Systems (HDSS) site in northwestern Burkina Faso. Eligible participants were aged 40 years or older and had been primarily resident in a household within the HDSS area for at least the past 6 months before the baseline survey and were selected from the 2015 HDSS household census using a stratified random sample of adults living in unique households within the area. Participants were interviewed in their homes in 2018 (baseline), 2021 (follow-up), or both. We derived the Fried frailty score for each participant at each timepoint using data on grip strength, gait speed, self-reported weight loss, self-reported exhaustion, and physical activity, and described changes in frailty status (no frailty, pre-frailty, or frailty) between 2018 and 2021. We used multivariate regression models to assess factors (ie, sex, age, marital status, educational attainment, wealth quintile, WHO Disability Assessment Schedule (WHODAS) score, and multimorbidity) associated with frailty progression (either worsening frailty status or dying, compared with frailty status remaining the same or improving) and with mortality, and developed sequential models: unadjusted, adjusting for sociodemographic factors (sex, age, marital status, educational attainment, and wealth quintile), and adjusting for sociodemographic factors, disability, and multimorbidity. FINDINGS: Between May 25 and July 19, 2018, and between July 1 and Aug 22, 2021, 5952 individuals were invited to participate: 1709 (28·7%) did not consent, 1054 (17·8%) participated in 2018 only and were lost to follow-up, 1214 (20·4%) participated in 2021 only, and 1975 (33·2%) were included in both years or died between years. Of 1967 participants followed up with complete demographic data, 190 (9·7%) were frail or unable to complete the frailty assessment in 2018, compared with 77 (3·9%) in 2021. Between 2018 and 2021, frailty status improved in 567 (28·8%) participants and worsened in 327 (16·6%), and 101 (5·1%) participants died. The relative risk of frailty status worsening or of dying (compared with frailty impRoving or no change) increased with age and WHODAS score, whereas female sex appeared protective. After controlling for all sociodemographic factors, multimorbidity, and WHODAS score, odds of mortality were 1·07 (odds ratio 2·07, 95% CI 1·05-4·09) times higher among pre-frail individuals and 1·1 (2·21, 0·90-5·41) times higher among frail individuals than among non-frail individuals. INTERPRETATION: Frailty status was highly dynamic in this low-income setting and appears to be modifiable. Given the rapid increase in the numbers of older adults in low-income or middle-income countries, understanding the behaviour of frailty in these settings is of high importance for the development of policies and health systems to ensure the maintenance of health and wellbeing in ageing populations. Future work should focus on designing context-appropriate interventions to improve frailty status. FUNDING: Alexander Von Humboldt Foundation, Institute for Global Innovation, University of Birmingham, and Wellcome Trust.

Disability transitions and health expectancies among adults 45 years and older in Malawi: a cohort-based model.

BACKGROUND: Falling fertility and increasing life expectancy contribute to a growing elderly population in sub-Saharan Africa (SSA); by 2060, persons aged 45 y and older are projected to be 25% of SSA's population, up from 10% in 2010. Aging in SSA is associated with unique challenges because of poverty and inadequate social supports. However, despite its importance for understanding the consequences of population aging, the evidence about the prevalence of disabilities and functional limitations due to poor physical health among older adults in SSA continues to be very limited. METHODS AND FINDINGS: Participants came from 2006, 2008, and 2010 waves of the Malawi Longitudinal Survey of Families and Health, a study of the rural population in Malawi. We investigate how poor physical health results in functional limitations that limit the day-to-day activities of individuals in domains relevant to this subsistence-agriculture context. These disabilities were parameterized based on questions from the SF-12 questionnaire about limitations in daily living activities. We estimated age-specific patterns of functional limitations and the transitions over time between different disability states using a discrete-time hazard model. The estimated transition rates were then used to calculate the first (to our knowledge) microdata-based health expectancies calculated for SSA. The risks of experiencing functional limitations due to poor physical health are high in this population, and the onset of disabilities happens early in life. Our analyses show that 45-y-old women can expect to spend 58% (95% CI, 55%-64%) of their remaining 28 y of life (95% CI, 25.7-33.5) with functional limitations; 45-y-old men can expect to live 41% (95% CI, 35%-46%) of their remaining 25.4 y (95% CI, 23.3-28.8) with such limitations. Disabilities related to functional limitations are shown to have a substantial negative effect on individuals' labor activities, and are negatively related to subjective well-being. CONCLUSIONS: Individuals in this population experience a lengthy struggle with disabling conditions in adulthood, with high probabilities of remitting and relapsing between states of functional limitation. Given the strong association of disabilities with work efforts and subjective well-being, this research suggests that current national health policies and international donor-funded health programs in SSA inadequately target the physical health of mature and older adults.

Disability and morbidity among US birth cohorts, 1998-2018: A multidimensional test of dynamic equilibrium theory.

A substantial body of prior research has explored patterns of disability-free and morbidity-free life expectancy among older populations. However, these distinct facets of later-life health are almost always studied in isolation, even though they are very likely to be related. Using data from the US Health and Retirement Study and a multistate life table approach, this paper explores the interactions between disability, morbidity, and mortality by sex and education among four successive US birth cohorts, born from 1914 to 1923 to 1944-1953 and compared in the periods 1998-2008 and 2008-2018. We find little compression of disability but a marked expansion of morbidity across cohorts. However, disability-free life expectancy (DFLE) among those living with chronic morbidities has increased, even though at the population-level DFLE is largely unchanged. Broadly, these patterns suggest that successive cohorts of older populations in the US are experiencing a dynamic equilibrium, where the link between chronic morbidities and disability has weakened over successive cohorts. Investigating patterns by educational attainment, we find marked disparities where the least educated individuals not only live significantly fewer years free of disabilities or chronic morbidities but also have experienced an expansion in morbidity and disability. Our findings suggest that the future trajectory of disability-free life expectancy in the US is increasingly contingent on efforts to improve disease management and control the severe consequences of chronic morbidities.

Impact of diabetes on longevity and disability-free life expectancy among older South African adults: A prospective longitudinal analysis.

AIMS: We seek to understand the coexisting effects of population aging and a rising burden of diabetes on healthy longevity in South Africa. METHODS: We used longitudinal data from the 2015 and 2018 waves of the "Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa" (HAALSI) study to explore life expectancy (LE) and disability-free life expectancy (DFLE) of adults aged 45 and older with and without diabetes in rural South Africa. We estimated LE and DFLE by diabetes status using Markov-based microsimulation. RESULTS: We find a clear gradient in remaining LE and DFLE based on diabetes status. At age 45, a man without diabetes could expect to live 7.4 [95% CI 3.4 - 11.7] more years than a man with diabetes, and a woman without diabetes could expect to live 3.9 [95% CI: 0.8 - 6.9] more years than a woman with diabetes. Individuals with diabetes lived proportionately more years subject to disability than individuals without diabetes. CONCLUSIONS: We find large and important decrements in disability-free aging for people with diabetes in South Africa. This finding should motivate efforts to strengthen prevention and treatment efforts for diabetes and its complications for older adults in this setting.

Differences in healthy longevity by HIV status and viral load among older South African adults: an observational cohort modelling study.

BACKGROUND: The population of people living with HIV in South Africa is rapidly ageing due to increased survivorship attributable to antiretroviral therapy (ART). We sought to understand how the combined effects of HIV and ART have led to differences in healthy longevity by HIV status and viral suppression in this context. METHODS: In this observational cohort modelling study we use longitudinal data from the 2015 baseline interview (from Nov 13, 2014, to Nov 30, 2015) and the 2018 longitudinal follow-up interview (from Oct 12, 2018, to Nov 7, 2019) of the population-based study Health and Ageing in Africa: a Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) to estimate life expectancy and disability-free life expectancy (DFLE) of adults aged 40 years and older in rural South Africa. Respondents who consented to HIV testing, responded to survey questions on disability, and who were either interviewed in both surveys or who died between survey waves were included in the analysis. We estimate life expectancy and DFLE by HIV status and viral suppression (defined as <200 copies per mL) using Markov-based microsimulation. FINDINGS: Among the 4322 eligible participants from the HAALSI study, we find a clear gradient in remaining life expectancy and DFLE based on HIV serostatus and viral suppression. At age 45 years, the life expectancy of a woman without HIV was 33·2 years (95% CI 32·0-35·0), compared with 31·6 years (29·2-34·1) a woman with virally suppressed HIV, and 26·4 years (23·1-29·1) for a woman with unsuppressed HIV; life expectancy for a 45 year old man without HIV was 27·2 years (25·8-29·1), compared with 24·1 years (20·9-27·2) for a man with virally suppressed HIV, and 17·4 years (15·0-20·3) for a man with unsuppressed HIV. Men and women with viral suppression could expect to live nearly as many years of DFLE as HIV-uninfected individuals at ages 45 years and 65 years. INTERPRETATION: These results highlight the tremendous benefits of ART for population health in high-HIV-prevalence contexts and reinforce the need for continued work in making ART treatment accessible to ageing populations. FUNDING: National Institutes of Health.