Expansion of disability across successive Mexican birth cohorts: a longitudinal modelling analysis of birth cohorts born 10 years apart

Disability and its impact on life expectancy: heterogeneity across Mexican states

BACKGROUND

The percentage of the world's population with disabilities is estimated to be 16%, although its distribution and intensity varies within nations. We aim to disentangle the degree and types of disabilities, estimate the years spent with more severe disabilities, and analyze their distribution across states and between sexes in Mexico.

METHODS

The Mexican Census of 2020 includes information on disabilities, which allows the study of its national distribution. We used life tables and the Sullivan method to calculate the number of years spent with disability (NYSD) and its percentage with respect to life expectancy for each state and each sex.

RESULTS

In Mexico, the population with disabilities is estimated to be 16.5%. Of this total, 69% have milder disabilities, while the remaining 31% have more severe disabilities. At age eighteen, there is a higher NYSD from more severe disabilities for females with 5.67 years (95% CI 5.66 to 5.69) as opposed to males with 3.66 years (95% CI 3.65 to 3.67). Across states, a more homogeneous distribution with lower NYSD is observed for men (between 2.44 and 5.69 years) than for women (4.14 and 8.08 years). A north-south division can also be observed, with particularly notorious disadvantages among coastal states, which is more distinctive among women.

CONCLUSIONS

This study shows that comparing the number of years spent with disability and the total life expectancy between subpopulations is essential for monitoring the well-being of aging populations, guiding policy decisions, and promoting a society that values and supports all individuals, regardless of their abilities.

Inequalities in Disability-Free and Disabling Multimorbid Life Expectancy in Costa Rica, Mexico, and the United States

OBJECTIVES

To better understand variations in multimorbidity severity over time, we estimate disability-free and disabling multimorbid life expectancy (MMLE), comparing Costa Rica, Mexico, and the United States (US). We also assess MMLE inequalities by sex and education.

METHODS

Data come from the Costa Rican Study on Longevity and Healthy Aging (2005-2009), the Mexican Health and Aging Study (2012-2018), and the Health and Retirement Study (2004-2018). We apply an incidence-based multistate Markov approach to estimate disability-free and disabling MMLE and stratify models by sex and education to study within-country heterogeneity. Multimorbidity is defined as a count of 2 or more chronic diseases. Disability is defined using limitations in activities of daily living.

RESULTS

Costa Ricans have the lowest MMLE, followed by Mexicans, then individuals from the US. Individuals from the US spend about twice as long with disability-free multimorbidity compared with individuals from Costa Rica or Mexico. Females generally have longer MMLE than males, with particularly stark differences in disabling MMLE. In the US, higher education was associated with longer disability-free MMLE and shorter disabling MMLE. We identified evidence for cumulative disadvantage in Mexico and the US, where sex differences in MMLE were larger among the lower educated.

DISCUSSION

Substantial sex and educational inequalities in MMLE exist within and between these countries. Estimating disability-free and disabling MMLE reveals another layer of health inequality not captured when examining disability and multimorbidity separately. MMLE is a flexible population health measure that can be used to better understand the aging process across contexts.

Rural and urban differences in lifetime occupation and its influence on mortality among Mexican adults

OBJECTIVE

To determine how primary lifetime occupation type is associated with mortality, and how the relationship varies by rural and urban dwelling.

MATERIALS AND METHODS

Data come from 2001-2018 Mexican Health and Aging Study (adults aged 50+, n=11 094). We created five occupation categories. Cox proportional hazard models predicted mortality using baseline covariates.

RESULTS

In both rural and urban settings, participants with manual jobs, such as agriculture and production/industrial jobs, had an increased risk of mortality compared to those with administrative/professional jobs. In urban settings, participants in the domestic/service and no main job categories had higher risk of mortality than those in the administrative/professional category. For men these differences remained, but not for women.

CONCLUSION

In a context of rural and urban demographic shifts, it is crucial to consider the implications that occupation as a socioeconomic factor can have on health and to identify the most vulnerable groups.

Comparison of the Physical Function Trajectories in Three Birth Cohorts of Chinese Older Adults: A 14-Year Longitudinal Study

OBJECTIVES

It remains uncertain whether the favorable trend of reduction in physical disabilities has become reversed in the recent-born cohorts of older adults. This study aimed to compare the rate of decline with time in self-reported Instrumental Activity of Daily Living (IADL) difficulties, objective measurement of gait speed and grip strength, in three birth cohorts of Chinese older adults.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

Four thousand Chinese older adults aged 65 years or above in three birth cohorts (1934-1938, 1929-1933, 1905-1928) were recruited from the community in Hong Kong.

MEASUREMENTS

Grip strength, gait speed and IADL difficulties were measured between 2001 to 2017. Joint models were used to examine the trajectories of grip strength, gait speed and IADL difficulties over time, and the interaction effect of age-by-cohort (or also age2-by-cohort) was also examined.

RESULTS

The recently born cohort (1934 - 1938) had worse grip strength and more IADL difficulties at the same age than the earlier two cohorts (1929 - 1933; 1905 - 1928). Furthermore, the most recently born cohort also followed a more rapid decline longitudinally with a greater decline observed in gait speed, grip strength and IADL difficulties for women whereas a greater decline in grip strength and IADL difficulties for men.

CONCLUSIONS

The continuous improvement of physical limitations in old age may have halted and there appears to be a reversal of this favourable trend in the recent born cohort of older adults living in Hong Kong.

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.

Population-level impact of adverse early life conditions on adult healthy life expectancy in low- and middle-income countries

Evidence from theories of Developmental Origins of Health and Disease (DOHaD) suggests that experiencing adverse early life conditions subsequently leads to detrimental adult health outcomes. The bulk of empirical DOHaD literature does not consider the nature and magnitude of the impact of adverse early life conditions at the population level. In particular, it ignores the distortion of age and cohort patterns of adult health and mortality and the increased load of chronic illness and disability that ensues. In this paper, we use a microsimulation model combined with empirical estimates of incidence and prevalence of obesity, type 2 diabetes, and associated disability in low- and middle-income countries to assess the magnitude of delayed effects on adult healthy life expectancy and on compression (or expansion) of morbidity at older ages. The main goal is to determine if, in what ways, and to what extent delayed effects due to early conditions can influence cohorts' chronic illness and disability profiles.

Population-level impact of adverse early life conditions on adult healthy life expectancy in low- and middle-income countries

Evidence from theories of Developmental Origins of Health and Disease (DOHaD) suggests that experiencing adverse early life conditions subsequently leads to detrimental adult health outcomes. The bulk of empirical DOHaD literature does not consider the nature and magnitude of the impact of adverse early life conditions at the population level. In particular, it ignores the distortion of age and cohort patterns of adult health and mortality and the increased load of chronic illness and disability that ensues. In this paper, we use a microsimulation model combined with empirical estimates of incidence and prevalence of obesity, type 2 diabetes, and associated disability in low- and middle-income countries to assess the magnitude of delayed effects on adult healthy life expectancy and on compression (or expansion) of morbidity at older ages. The main goal is to determine if, in what ways, and to what extent delayed effects due to early conditions can influence cohorts' chronic illness and disability profiles.

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.

Transitions of disability, disability-free life expectancy and health insurance among adults aged 50 and older in Mexico: a multistate life table analysis

OBJECTIVES

To analyse the transitions of disability onset and recovery, estimate life expectancy (LE) with and without disability and explore the relation between insurance and disability patterns in the population aged 50+ in Mexico.

DESIGN

Multistate life table analysis of data from a longitudinal cohort survey.

SETTING

Data came from the Mexican Health and Aging Study, a longitudinal and representative survey of older adults in Mexico.

PARTICIPANTS

10 651 individuals aged 50+ interviewed in 2012 and 2015, including those who died between waves.

PRIMARY AND SECONDARY OUTCOME MEASURES

Disability is measured using the activities of daily living (ADL) scale. Transition rates between disability free, ADL disabled and death were employed to estimate total life expectancy (TLE) and disability-free life expectancy (DFLE).

RESULTS

46% of the individuals who reported an ADL limitation in 2012 recover from disability by 2015. TLE at age 60 for people without ADL limitations is 30 years (95% CI 28.9 to 31), out of which 4.7 years (95% CI 4.1 to 5.4) are lived with ADL limitations, while TLE at age 60 in the initially disabled is 18.7 years (95% CI 17.3 to 20), with 9.4 years (95% CI 8.4 to 10.3) lived with disability. DFLE at age 60 in people with social security is 24.2 years (95% CI 23.3 to 25.2), in people with public insurance is 24.6 years (95% CI 23.7 to 25.4) and in uninsured people is 26.9 years (95% CI 25.9 to 27.9).

CONCLUSIONS

In Mexico, a substantial proportion of ADL disabled individuals recover from disability. Nevertheless, initially disabled individuals have a considerably lower DFLE regardless of age when compared with initially active individuals. There appeared to be no differences in terms of disability and LEs between the individuals with social security and public insurance.

Effect of Demographic and Health Dynamics on Cognitive Status in Mexico between 2001 and 2015: Evidence from the Mexican Health and Aging Study

Sources of health disparities such as educational attainment, cardiovascular risk factors, and access to health care affect cognitive impairment among older adults. To examine the extent to which these counteracting changes affect cognitive aging over time among Mexican older adults, we examine how sociodemographic factors, cardiovascular diseases, and their treatment relate to changes in cognitive function of Mexican adults aged 60 and older between 2001 and 2015. Self and proxy respondents were classified as dementia, cognitive impairment no dementia (CIND), and normal cognition. We use logistic regression models to examine the trends in dementia and CIND for men and women aged 60 years or older using pooled national samples of 6822 individuals in 2001 and 10,219 in 2015, and sociodemographic and health variables as covariates. We found higher likelihood of dementia and a lower risk of CIND in 2015 compared to 2001. These results remain after adjusting for sociodemographic factors, cardiovascular diseases, and their treatment. The improvements in educational attainment, treatment of diabetes and hypertension, and better access to health care in 2015 compared to 2001 may not have been enough to counteract the combined effects of aging, rural residence disadvantage, and higher risks of cardiovascular disease among older Mexican adults.

Spousal Support, Spousal Strain, and Loneliness in Older Mexican Couples

OBJECTIVES

A growing body of research has identified factors related to loneliness among older adults. Fewer have investigated predictors of loneliness within married couples. This analysis investigates how spousal support and strain relate with loneliness within older couples (age 50+), and whether these associations are modified by functional limitation. The study focuses on Mexico, a country experiencing rapid aging occurring alongside historically limited institutional support for older adults, and where traditional gender roles extend to marriage.

METHODS

The analytic sample consisted of 3,584 husband-wife dyads from the 2012 and 2015 Mexican Health and Aging Study. Loneliness was measured using the Three-Item Loneliness Scale. Associations between spousal support, strain, and loneliness were estimated within husband-wife dyads using the Actor-Partner Interdependence Model.

RESULTS

Experiencing more spousal support was associated with less loneliness, whereas experiencing spousal strain was associated with more loneliness 3 years later among married adults. The associations between spousal support/strain and loneliness were stronger among husbands with limitations in activities of daily living (ADL) when compared to their counterparts without ADL limitations.

DISCUSSION

Among married adults, spousal support and strain may be important factors to understand loneliness within marriage. Effects should be interpreted within the context of functional limitation.

Recovery from physical limitations among older Mexican adults

OBJECTIVES

This paper examines the key determinants of the likelihood of recovery from a physical disability among older adults.

METHODS

Data come from the Mexican Health and Aging Study (MHAS), a national sample of adults born in 1951 or earlier, including a baseline survey in 2001 and follow-ups in 2003, 2012 and 2015. At baseline, we divided our sample of older adults aged 60+ by dimensions of physical limitations (ADLs, IADLs, mobility) and classified respondents as having physical limitations in zero, one, two or three dimensions. Each respondent was then categorized as "same", "worse", "improved" or "died" depending on the number of physical dimensions with a limitation in a 2-year span (2001-2003) and again, separately, in a 3-year span (2012-2015). We then used a multinomial logistic regression to analyze the relative risk of transitioning from one category to another.

FINDINGS

Around 21 % of our sample exhibited some recovery in 2003 and around 20 % recovered in 2015. Age, gender, poor self-rated health, depression and some chronic conditions were significant for shifting the relative risk from staying the same to getting worse, dying or even improving.

CONCLUSIONS

Disability from a physical limitation is a reversible and dynamic process. Our results reflect the importance of considering the dimensions of physical ability while analyzing recovery, and illustrate that the presence of a chronic condition or depressive symptoms does not necessarily imply permanent disability.