The effect of educational attainment on cognition of older adults: results from the Mexican Health and Aging Study 2001 and 2012

Disability-Adjusted Life Expectancy and Cognitive Function among Community-Dwelling Adults

We aimed to calculate disability-adjusted life expectancy (DALE) for Korean older adults based on their sex, educational attainment, and residential region across their cognitive status. We included 3,854 participants (aged 65-91 years) from the Korean Longitudinal Study of Aging's seventh survey data. The participant's cognitive function status (normal, moderately impaired, or severely impaired) was determined based on cognitive examination and physical function independence, which was used to calculate their DALE. Females with normal cognition had higher DALE (7.60 years, Standard Deviation (SD) = 3.88) than males (6.76, SD = 3.40); however, both sexes had comparable DALE for cognitive impairment. In contrast, the DALE values increased with higher educational achievements. Regarding residential areas, the DALE value for participants with normal cognition and moderate impairment was the highest among urban dwellers, while DALE for participants with severely impaired cognitive function was highest among rural dwellers; however, there were no statistically significant differences based on residential conditions. Our findings suggest that demographic characteristics should be considered when developing health policies and treatment strategies to meet the needs of the aging population in Korea.

My Parent, Myself, or My Child: Whose Education Matters Most for Trajectories of Cognitive Aging in Middle Age?

The growing body of evidence linking intergenerational education and late-life cognitive decline is almost exclusively from high-income countries, despite rapid intergenerational changes in education in low- and middle-income countries (LMICs). We used data from the Mexican Health and Aging Study (n = 8,822), a cohort study of Mexican adults aged ≥50 years (2001-2018), to evaluate whether parental education (none vs. any formal schooling), one's own education (less than primary school vs. completion of primary school), or an adult child's education (less than high school vs. completion of high school) was associated with verbal memory z scores. We used linear mixed models with inverse probability of attrition weights. Educational attainment in all 3 generations was associated with baseline verbal memory scores, independent of the prior generation's education. Lower parental (β = -0.005, 95% confidence interval: -0.009, -0.002) and respondent (β = -0.013, 95% confidence interval: -0.017, -0.010) educational level were associated with faster decline in delayed (but not immediate) verbal memory z scores. Associations between adult child's education and respondent's verbal memory decline varied by exposure specification. The educational attainment of parents and adult children may influence the cognitive aging of middle-aged and older adults in LMICs. These results have important implications given recent structural shifts in educational attainment in many LMICs.

Physical exercise and cognition in older adults, a scientific approach scanty reported in Latin America and Caribbean populations

The advancement of public services, including the increased accessibility of health services, has led to a rise in life expectancy globally. As a result, aging populations are becoming more prevalent, raising concerns about cognitive decline. Fortunately, non-pharmacological methods, such as physical exercise, have been shown to mitigate the effects of aging on the brain. In this perspective article, we examined meta-analyses on the impact of physical exercise on cognition in older adults. The results indicate that combined exercise (i.e., aerobic plus strength training), has a significant positive effect on overall cognition and executive function. However, we found a lack of scientific studies on this topic in Latin American and Caribbean countries. Therefore, there is a pressing need for research to identify the feasibility of physical exercise interventions to improve cognitive skills in older adults from these regions.

Late-life food insecurity and cognition: exploring timing, duration, and mechanisms among older Mexican adults

BACKGROUND

Food insecurity (FI) remains a global public health problem. FI is more prevalent in low-and middle-income countries than high-income countries. FI is related with worse cognitive outcomes including cognitive function, cognitive decline, and cognitive impairment. Few studies have sought to identify how patterns of FI relate with cognitive function in old age and the potential mechanisms underlying this association.

METHODS

Data from the 2015 and 2018 waves of the Mexican Health and Aging Study (n = 9,654, age 50+) were used in this study. Reports of FI in 2015 and 2018 were combined to create four patterns of FI groups: "persistently food secure", "became food secure", "became food insecure", and "persistently food insecure". Linear regression was used to estimate associations between patterns of FI and cognitive task performance. The mediating roles of depressive symptoms, body mass index, and chronic conditions were tested using Karlson, Holm, and Breen methodology.

RESULTS

Approximately half of the sample were persistently food secure, 17% became food secure, 14% became FI, and 15% experienced persistent FI. When adjusting for demographic/socioeconomic confounders, persistent FI related with worse Verbal Learning, Verbal Recall, Visual Scanning, and Verbal Fluency performance compared to the persistently food secure. Becoming FI related with worse Verbal Learning, Visual Scanning, and Verbal Fluency. Mediation analyses provided support for depressive symptoms mediating associations between FI and poorer cognition, where 48% of the association between persistent FI and worse Verbal Recall performance was attributed to higher depressive symptoms. Becoming food secure was not associated with cognitive performance compared to the persistently food secure.

CONCLUSIONS

FI may represent an important modifiable risk factor for poorer cognitive outcomes among older adults. Public health efforts should focus on providing stable food access to older adults, especially those living in poverty.

The Impact of Education and Insurance Status on Past-Year Dental Visits Among Older Mexican Adults: Results From the 2001 and 2012 Mexican Health and Aging Study

Objective: This study assessed past-year dental visits among older Mexican adults from the Mexican Health and Aging Study (MHAS). MHAS is a nationally representative cohort study of adults 50 years and older from Mexico. Methods: Baseline data from 2001 were compared with 2012 data. Binary logistic regression identified significant predictors of past-year dental visits. Decomposition techniques examined factors that contributed to changes in dental visits between 2001 and 2012. Results: Education and insurance status were positively associated with past-year dental visits, while decomposition results showed that population composition (more adults receiving insurance and higher education over time) contributed to the increased prevalence of dental visits between 2001 and 2012. Discussion: Education and insurance are critical factors that govern access to oral healthcare. After the provision of universal dental coverage by Mexico's Seguro Popular in 2003, our results may reflect promising effects of such programs, which can inform future policies in Mexico and other settings.

Cognitive life expectancy by educational attainment in Mexican adults aged 60 and older

OBJECTIVE

To estimate cognitively healthy life expectancy (CHLE), cognitive impairment life expectancy (CILE), and dementia life expectancy (DLE) in Mexican adults aged 60 and older stratified by educational attainment.

MATERIALS AND METHODS

The data were obtained from Waves 1 (2001) to 5 (2018) of the Mexican Health and Aging Study. The life expectancy was estimated using a multistate life table analysis.

RESULTS

CHLE at age 60 increased with higher educational attainment and ranged from 17.9 to 24.4 years in female participants, and 17.2 to 21.3 in male participants. The CILE and DLE decreased with greater educational attainment. The CILE ranged from 0.7 to 2.8 years in female participants and 0.7 to 2.6 in male participants.

CONCLUSIONS

Older adults in Mexico with higher education live more years with good cognitive health and fewer years with cognitive impairment and dementia. Education has a stronger effect on the length of cognitively healthy life expectancies than on total life expectancies.

Negative wealth shocks in later life and subsequent cognitive function in older adults in China, England, Mexico, and the USA, 2012-18: a population-based, cross-nationally harmonised, longitudinal study

BACKGROUND

Household wealth is positively related to cognitive health outcomes in later life. However, the association between negative wealth shocks and cognitive function in later life, and whether this association might differ across countries at different levels of economic development, is unclear. We aimed to investigate whether negative wealth shocks in later life are associated with cognitive function in older adults in China, England, Mexico, and the USA, and whether this association is modified by country income level.

METHODS

For this population-based, cross-nationally harmonised, longitudinal study, data were analysed from core interviews of the population-based US Health and Retirement Study (2012 and 2016) and its partner studies in China (the China Health and Retirement Longitudinal Study; 2015 and 2018), England (the English Longitudinal Study of Ageing; 2012 and 2016), and Mexico (Mexican Health and Aging Study; 2012 and 2015-16), and their respective Harmonized Cognitive Assessment Protocols (HCAPs). Negative wealth shocks over the follow-up periods of the respective cohorts were defined in two ways: an extreme loss of 75% or greater from the baseline amount of wealth, and a decline in within-population wealth quintile rank. The primary outcome was the harmonised general cognitive function (GCF) factor score, which was constructed with factor analysis on the HCAP neuropsychological assessments of memory, orientation, attention, executive function, and verbal fluency performance (mean 0; SD 1). We used sampling-weighted, multivariable-adjusted linear models to examine associations.

FINDINGS

Data from 9465 participants were included in this analysis: 3796 from China, 1184 from England, 1193 from Mexico, and 3292 from the USA. The mean baseline age of participants was 68·5 (SD 5·4) years in China (49·8% women), 72·0 (7·0) years in England (54·6% women), 70·6 (6·8) years in Mexico (55·1% women), and 72·7 (7·5) years in the USA (60·4% women). A wealth loss of 75% or greater was negatively associated with subsequent cognitive function in the USA (β -0·16 SD units; 95% CI -0·29 to -0·04) and China (-0·14; -0·21 to -0·07), but not in England (-0·01; -0·24 to 0·22) or Mexico (-0·11; -0·24 to 0·03). Similarly, within-population wealth quintile rank declines were negatively associated with subsequent cognitive function in the USA (β -0·07 per quintile rank decline; 95% CI -0·11 to -0·03) and China (β -0·07; -0·09 to -0·04), but not in England (-0·05; -0·11 to 0·01) or Mexico (-0·03; -0·07 to 0·01).

INTERPRETATION

The impact of wealth shocks in later life on subsequent lower level of cognitive function of older adults in China, England, Mexico, and the USA differed across macro-level socioeconomic structures. These findings suggest that government policies and social safety nets in countries with different levels of economic development might have a role in protecting older adults from adverse health effects of wealth losses in later life.

FUNDING

US National Institute on Aging, US National Institutes of Health.

Education and cognitive function among older adults in Brazil and Mexico

Education is protective against cognitive impairment. We used nationally representative data from Mexico and Brazil to assess the association between education and cognitive function. The sample included adults ≥ 50 years from the Brazilian Longitudinal Study of Aging (ELSI) and the Mexican Health and Aging Study (MHAS). Participants were classified as cognitively impaired or not impaired. We used logistic regression models to estimate the association between education and cognitive function. Education level was higher in MHAS than in ELSI. Participants with at least 1 year of education were less likely to have cognitive impairment than those with no formal education in both cohorts. Men in ELSI had higher odds for cognitive impairment compared to men in MHAS. In both cohorts, higher educational level was associated with lower odds of cognitive impairment compared to no formal education. Sex was an effect modifier in MHAS but not in ELSI.

HIGHLIGHTS

Cognitive test batteries were harmonized using a regression-based approach.Even very low levels of education were associated with reduced odds of cognitive impairment compared to no formal education.Brazilians were more likely to have cognitive impairment than Mexicans given the same education level.The differences in the association of education with cognition between Brazil and Mexico were only observed among men.

Gender, Personality, and Cognitive Resilience Against Early-Life Disadvantage

OBJECTIVES

Early-life disadvantage (ELD) relates to lower late-life cognition. However, personality factors, including having an internal locus of control (LOC) or a conscientious personality, relate to resilience and effective stress coping. We explore whether personality factors convey resilience against the negative effects of ELD on cognition, by gender, in Mexico.

METHODS

Using the 2015 Mexican Health and Aging Study, we estimated expected cognition using multiple ELD markers to identify a subsample in the lowest quartile of expected cognition given ELD (n = 2,086). In this subsample, we estimated cross-sectional associations between personality and having above-median observed cognitive ability (n = 522) using logistic regression.

RESULTS

Among those in the lowest quartile of expected cognition, a more internal LOC (β = 0.32 [men] and β = 0.44 [women]) and conscientious personality (β = 0.39 [men] and β = 0.17 [women]) were significantly associated with having above-median cognitive ability in models adjusted for demographic confounders. Larger benefits of conscientiousness were observed for men than women. Associations between personality and having above-median cognitive ability remained statistically significant after further adjustment for health, stress, and cognitive stimulation variables, regardless of gender.

DISCUSSION

Personality factors may convey resilience among individuals who experienced ELD, potentially breaking the link between ELD and worse late-life cognition. Structural factors and gender roles may affect how much women benefit from personality factors.

Incidence of post-stroke cognitive impairment in patients with first-ever ischemic stroke: a multicenter cross-sectional study in China

Background

Post-stroke cognitive impairment (PSCI) is a common sequela after stroke. China has a large population of stroke survivors, but a large-scale survey on the incidence and risk factors for PSCI has not been undertaken. We aimed to calculate the incidence and risk factors for vascular cognitive symptoms among first-ever stroke survivors in China through a multicenter cross-sectional study.

Methods

From May 1, 2019 to November 30, 2019, patients with a clinical diagnosis of first-ever ischemic stroke were recruited from 563 hospitalized-based stroke center networks in 30 provinces of China. Cognitive impairment was measured by 5-min National Institute of Neurological Disease and Stroke-Canadian Stroke Network (NINDS-CSN) at 3-6 months after the indexed stroke. Stepwise multivariate regression and stratified analysis were performed to assess the association between PSCI and demographic variables.

Findings

A total of 24,055 first-ever ischemic stroke patients were enrolled, with an average age of 70.25 ± 9.88 years. The incidence of PSCI as per the 5-min NINDS-CSN was 78.7%. Age ≥75 years old (OR: 1.887, 95%CI: 1.391-2.559), western regional residence (OR: 1.620, 95%CI: 1.411-1.860) and lower education level were associated with increased PSCI risk. Hypertension might be related to non-PSCI (OR: 0.832, 95%CI: 0.779-0.888). For patients under 45 years old, unemployment was an independent risk factor for PSCI (OR: 6.097, 95%CI: 1.385-26.830). For patients who were residents of the southern region (OR: 1.490, 95%CI: 1.185-1.873) and non-manual workers (OR: 2.122, 95%CI: 1.188-3.792), diabetes was related to PSCI.

Interpretation

PSCI is common in Chinese patients with first-ever stroke, and many risk factors are related to the occurrence of PSCI.

Funding

The Beijing Hospitals Authority Youth Program (No. QMS20200801); Youth Program of the National Natural Science Foundation of China (No. 81801142); the Key Project of Science and Technology Development of China Railway Corporation (No. K2019Z005); The Capital Health Research and Development of Special (No. 2020-2-2014); Science and Technology Innovation 2030-Major Project (No. 2021ZD0201806).

Comparison of sex differences in cognitive function in older adults between high- and middle-income countries and the role of education: a population-based multicohort study

BACKGROUND

The extent to which education explains variations in sex differences in cognitive function between countries at different levels of economic development is unknown. We examined the role of education in sex differences in four cognitive domains in high- and middle-income countries.

METHODS

Analyses were based on 70,846 participants, aged 60 years and older, in cohort studies from a high-income (United States) and four middle-income countries (Mexico, Brazil, China, and India). We used weighted linear models to allow nationally-representative comparisons of sex differences in orientation, memory, attention, and fluency using the United States as the reference, before and after adjustment for education, and after stratification by education.

RESULTS

Females had lower levels of education than males in all countries, particularly in India. Before adjustment for education, sex differences in orientation and attention in all middle-income countries, memory in Brazil, China, and India, and fluency in India were less favourable to females than in the United States (P < 0.010). For example, females outperformed males in memory in the United States (mean difference [male-female scores] = -0.26 standard deviations [95% CI -0.30, -0.22]) but not in China (0.15 [0.09, 0.21]) or India (0.16 [0.13, 0.19]). Adjustment for education attenuated these sex differences. In analyses stratified by education, there were minimal sex differences in the high education group in all countries.

CONCLUSION

Education contributes to larger female disadvantages in cognitive function at older ages in middle-income countries compared with the United States. Gender equity in education is an important target to reduce sex disparities in cognitive function globally.

Differences in the Cognitive Function of Mexican Adults Aged 60 and Older with Self-Reported Diabetes in 2001 and 2018

BACKGROUND

The prevalence of type 2 diabetes in Mexico has nearly doubled for adults aged ≥60. Increases in education and healthcare resources to manage chronic conditions have contributed to population-level increases in the cognitive functioning of older adults. However, research has not focused on older adults with chronic conditions such as diabetes.

OBJECTIVE

Our objective was to compare the cognitive functioning of Mexican adults aged ≥60 with diabetes in 2001 and 2018.

METHODS

Data came from Mexican Health and Aging Study. Our study used a cross-sectional design and included participants aged ≥60 with self-reported diabetes during the 2001 (n = 1,052, mean age = 68.4, female = 59.6%) and 2018 (n = 2,469, mean age = 70.6, female = 62.0%) observation waves. Five cognitive tests were used to create a score of global cognition. Generalized estimating equations were used to compare global cognition in 2001 to 2018.

RESULTS

Older adults in 2018 had more education and were more likely than older adults in 2001 to take oral medication for diabetes, insulin, and to check blood sugar weekly. Older adults in 2018 had higher global cognition than in 2001 when adjusting for age, gender, education, and health insurance coverage (b = 0.38, SE = 0.02). This statistically significant difference remained after adjusting for health conditions, health behaviors, and diabetes management behaviors.

CONCLUSIONS

Older adults in Mexico with self-reported diabetes in 2018 had higher cognitive function than in 2001. Future research is needed to investigate causes of the cohort differences in cognitive functioning among Mexican older adults with self-reported diabetes.

Predictors of Successful Memory Aging in Older Mexican Adults

Background

Research suggests a significant association between increasing age and memory impairments. Nevertheless, for some individuals, memory performance stays within or above the normative values of younger subjects. This is known as successful memory aging and is associated with specific neurophysiological features and psychological and lifestyle-related variables. To date, little is known about the association between successful memory aging and intrinsic capacity (IC) defined as “the composite of all the physical and mental (including psychosocial) capacities that an individual can draw on at any point in time” and resilience. Hence, the aim of this study was to determine if longitudinal associations between IC and successful memory aging and resilience exist and to find differences in cognitive performance between Mexican older adults with successful memory aging, older adults with average memory, and older adults with memory impairment.

Methods

Longitudinal data from 590 individuals from the third wave (2012) and the Mex-Cog subsample (2016) of the Mexican Health and Aging Study was analysed. Subjects were classified into 3 groups: (1) older adults with successful memory aging (SUMA), (2) older adults with average memory (AVMA), and (3) older adults with memory impairment (IMA). Cognitive domains of orientation, language, attention, constructional praxis, and executive function were evaluated. IC and resilience were measured using items from the MHAS battery. Analysis of variance and multinomial logistic regressions were used to find differences in IC and resilience across the memory aging groups.

Results

ANOVAs showed significant differences across the three cognitive performance groups in all cognitive domains. Multinomial logistic regression analyses revealed that respondents with higher scores in the psychological and cognitive domains of IC at baseline were more likely to have successful memory aging in the subsequent wave of the study. More resilient subjects in 2012 were not more likely to become a SUMA in 2016. However, this could be a result of the way resilience was measured.

Conclusion

Our main findings suggest that intrinsic capacity could be used as a predictor of successful memory aging specifically in the psychological and the cognitive domains. More longitudinal studies are needed to further examine these associations.

Feasibility and Preliminary Efficacy of a Multimodal Approach to Increase Physical Activity in Older Adults With Memory Complaints: The Education for Action Study

In this randomized controlled pilot trial, the authors explored the feasibility, technology compliance, and preliminary efficacy of the Education for Action (EDU-ACT), a multimodal intervention combining evidence-based strategies of physical activity (PA) education and coaching in PA levels over 4 weeks between EDU-ACT and control groups. The authors also assessed pre-post changes in neurocognitive function, functional mobility and dual-task performance, sleep and quality of life. Thirty-two sedentary older adults with memory complaints (age = 66 ± 5.3) completed the study (EDU-ACT = 18 and control = 14). The EDU-ACT adherence rate was 95%, and compliance of daily PA reporting was, on average, 22.7 days (94.6%). The EDU-ACT group demonstrated a significantly greater number of steps, processing speed, and dual-task performance when compared with controls (p < .05). In this study, a multimodal, evidence-based, low-cost intervention was feasible, well-accepted, with high adherence and compliance rates, and effective at promoting clinically meaningful increases in PA, for at least 1 month postintervention, in older adults with memory complaints.

Ethnoracial disparities in cognition are associated with multiple socioeconomic status-stress pathways

Systemic racism can have broad impacts on health in ethnoracial minorities. One way is by suppressing socioeconomic status (SES) levels through barriers to achieve higher income, wealth, and educational attainment. Additionally, the weathering hypothesis proposes that the various stressful adversities faced by ethnoracial minorities lead to greater wear and tear on the body, known as allostatic load. In the present study, we extend these ideas to cognitive health in a tri-ethnic sample of young adults-when cognition and brain health is arguably at their peak. Specifically, we tested competing mediation models that might shed light on how two key factors caused by systemic racism-SES and perceived stress-intersect to explain ethnoracial disparities in cognition. We found evidence for partial mediation via a pathway from SES to stress on episodic memory, working memory capacity, and executive function in Black Americans relative to non-Hispanic White Americans. Additionally, we found that stress partially mediated the ethnoracial disparities in working memory updating for lower SES Black and Hispanic Americans relative to non-Hispanic White Americans, showing that higher SES can sometimes reduce the negative effects stress has on these disparities in some cognitive domains. Overall, these findings suggest that multiple pathways exist in which lower SES creates a stressful environment to impact ethnoracial disparities cognition. These pathways differ depending on the specific ethnoracial category and cognitive domain. The present results may offer insight into strategies to help mitigate the late-life risk for neurocognitive disorders in ethnoracial minorities.

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.

Imputation Procedures for Cognitive Variables in the Mexican Health and Aging Study: Evaluating the Bias from Excluding Participants with Missing Data

Non-response of cognitive data in cohort studies is a barrier to cognitive aging research. We describe the procedures for the imputation of non-responses for cognitive data in the Mexican Health and Aging Study (MHAS). Data came from the 2001-2015 MHAS waves. We also describe the association of cognition with education, age, and other variables in 2015 with and without the imputed values. Between 12.3% and 37.9% of participants were missing data for at least one cognition variable. When we conducted the analysis with and without the imputed values, the relationships between education, age, and cognition were similar in direction and significance, but different in magnitude. Non-response of cognitive data is common and non-random in the MHAS. Investigators should use the data sets that include the imputed values, which are publicly available.

The Effect of Diabetes on the Cognitive Trajectory of Older Adults in Mexico and the United States

OBJECTIVES

To study the impact of diabetes on the long-term cognitive trajectories of older adults in 2 countries with different socioeconomic and health settings, and to determine whether this relationship differs by cognitive domains. This study uses Mexico and the United States to confirm if patterns hold in both populations, as these countries have similar diabetes prevalence but different socioeconomic conditions and diabetes-related mortality.

METHODS

Two nationally representative cohorts of adults aged 50 years or older are used: the Mexican Health and Aging Study for Mexico and the Health and Retirement Study for the United States, with sample sizes of 18,810 and 26,244 individuals, respectively, followed up for a period of 14 years. The outcome is cognition measured as a total composite score and by domain (memory and nonmemory). Mixed-effect linear models are used to test the effect of diabetes on cognition at 65 years old and over time in each country.

RESULTS

Diabetes is associated with lower cognition and nonmemory scores at baseline and over time in both countries. In Mexico, diabetes only predicts lower memory scores over time, whereas in the United States it only predicts lower memory scores at baseline. Women have higher total cognition and memory scores than men in both studies. The magnitude of the effect of diabetes on cognition is similar in both countries.

DISCUSSION

Despite the overall lower cognition in Mexico and different socioeconomic characteristics, the impact of diabetes on cognitive decline and the main risk and protective factors for poor cognition are similar in both countries.

The Sequence of Physical and Cognitive Impairment and the Association with Mortality Among Unimpaired Older Mexican Adults

BACKGROUND

Many older adults become physically and cognitively impaired. However, it is unclear whether unimpaired older adults are more likely to become physically or cognitively impaired first and if this sequence impacts mortality risk.

METHODS

Data came from the Mexican Health and Aging Study. The sample included 1,283 participants aged ≥60 years who were physically and cognitively unimpaired in 2001. Multinomial logistic regression was used to estimate probabilities of being unimpaired, cognitively impaired only, physically impaired only, or cognitively-physically impaired in 2003. Proportional hazard models were used to estimate mortality risk through 2015 according to physical and cognitive status in 2003.

RESULTS

The probabilities for being unimpaired, physically impaired only, cognitively impaired only, and cognitively-physically impaired in 2003 were 0.45, 0.22, 0.19, and 0.13, respectively. Older age, female sex, and arthritis were associated with significantly greater probability of becoming physically impaired only than cognitively impaired only in 2003. Cognitive impairment only (hazard ratio [HR] = 1.42, 95% confidence interval [CI] = 1.09-1.85) in 2003 but not physical impairment only (HR = 1.22, 95% CI = 0.94-1.58) was associated with greater mortality than being unimpaired in 2003. Cognitively-physically impaired participants had higher mortality risk than participants who were physically (HR = 1.58, 95% CI = 1.18-2.12) or cognitively (HR = 1.36, 95% CI = 1.01-1.84) impaired only.

DISCUSSION

The likelihood of becoming only physically or cognitively impaired over 2 years varies by demographic and health characteristics. The mortality risk for unimpaired older adults who become cognitively impaired only is similar to those who become physically impaired only. Research should determine if the sequence of cognitive and physical impairments is associated with other outcomes.

The gender gap in education and late-life cognition: Evidence from multiple countries and birth cohorts

We document side-by-side trends in the gender gap of educational achievement and late-life cognition across countries. By and large, we find that, within the cohorts born between 1920 and 1959, women have had significantly lower educational attainment than men, with the gap narrowing over time. Correspondingly, we estimate a pronounced tendency of women's cognition to improve over time relative to men. We investigate whether these co-movements are likely due to the narrowing gender gap in education inducing a relative improvement in women's cognition. The data offer little support for such a causal relation. We discuss possible third factors that may underlie the observed parallel trends in education and cognition gender gaps.