The Mexican Cognitive Aging Ancillary Study (Mex-Cog): Study Design and Methods

Mejía-Arango, Silvia; Nevarez, Rene; Michaels-Obregón, Alejandra; Trejo-Valdivia, Belém; Mendoza-Alvarado, Laura R; Sosa‐Ortíz, Ana Luisa; Martínez-Ruiz, Adrián; Wong, Rebeca

doi:10.1016/j.archger.2020.104210

Cited by 23 publications

(20 citation statements)

References 34 publications

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“…The above are valid measures of cognitive outcomes in Mexico 36 and have been widely used to assess cognitive function and decline in Mexico 37 . Analyses focus on scores across cognitive tasks at baseline as well as longitudinal change in cognitive scores (cognitive decline).…”

Section: Methodsmentioning

confidence: 99%

Solid cooking fuel use and cognitive decline among older Mexican adults

Sáenz

2021

Indoor Air

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Studies of air pollution and cognition often rely on measures from outdoor environments. Many individuals in low‐ and middle‐income countries are exposed to indoor air pollution from combustion of solid cooking fuels. Little is known about how solid cooking fuel use affects cognitive decline over time. This study uses data from the 2012, 2015, and 2018 Mexican Health and Aging Study (n = 14 245, age 50+) to assess how use of wood or coal for cooking fuel affects cognition of older adults relative to use of gas. It uses latent change score modeling to determine how using solid cooking fuel affected performance in Verbal Learning, Verbal Recall, Visual Scanning, and Verbal Fluency. Solid cooking fuel was used by 17% of the full sample but was more common in rural areas. Solid fuel users also had lower socioeconomic status. Compared to those using gas, solid fuel users had lower baseline scores and faster decline in Verbal Learning (β = −0.18, p < 0.05), Visual Scanning (β = −1.00, p < 0.001), and Verbal Fluency (β = −0.33, p < 0.001). Indoor air pollution from solid cooking fuels may represent a modifiable risk factor for cognitive decline. Policy should focus on facilitating access to clean cooking fuels.

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Section: Methodsmentioning

confidence: 99%

Solid cooking fuel use and cognitive decline among older Mexican adults

Sáenz

2021

Indoor Air

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“…The Mex-Cog study administers a harmonized cognitive assessment protocol currently used by other ongoing population-based longitudinal studies of aging around the world (Langa et al, 2020). As per Mex-Cog protocols (Mejia-Arango et al, 2020), participants who scored ≤10 on a modified version of the Mini-Mental State Examination (MMSE) (Mex-Cog, 2018) (n = 102) were considered severely impaired and were not administered the full cognitive battery, and therefore excluded from the analysis sample. Additional exclusion criteria included missing demographic (n = 17) or neuropsychological data (n = 23), and dementia classification at their MHAS 2015 visit (n = 93).…”

Section: Participantsmentioning

confidence: 99%

“…Participants completed a comprehensive cognitive assessment evaluating various cognitive domains such as memory, language, visuospatial function, and executive functioning (Table 1). Information regarding the selection process of the items that were included in the Mex-Cog cognitive battery can be found in their published protocols (Mejia-Arango et al, 2020). In brief, cognitive tests were selected based on their suitability for in-home application by trained interviewers, for their potential to be culturally adapted for rural and low-educated populations in Mexico, and to maximize harmonization with the Health and Retirement Study/Harmonized Cognitive Assessment Protocol study.…”

Section: Cognitive Assessmentmentioning

confidence: 99%

“…The Mex-Cog informant instrument included 28 items from the Community Screening Interview for Dementia (Hall et al, 1993) that asks about the participant's performance in everyday living, and an adapted version of the History and Aethiology Scale (Dewey & Copeland, 2001) to assess history of cognitive decline. Greater detail on the informant interview can be found on the Mex-Cog methodological document (Mejia-Arango et al, 2020;Mex-Cog, 2018).…”

Section: Informant Interviewmentioning

confidence: 99%

“…The Mexican Health and Aging Study (MHAS) started in 2001, with a nationally representative sample of Mexican adults aged ≥50, designed to prospectively evaluate the impact of disease on health, function, and mortality (Wong, Michaels-Obregon, & Palloni, 2015). In 2016, MHAS launched an Ancillary Study on Cognitive Aging in Mexico (Mex-Cog) among a representative sub-sample of MHAS participants (Mejia-Arango et al, 2020) with the primary goal to expand the knowledge about cognitive aging in Mexico through a comprehensive cognitive assessment. The Mex-Cog study provides a unique opportunity to estimate MCI in a large sample of Mexican adults with over 15 years of follow-up.…”

Section: Introductionmentioning

confidence: 99%

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Midlife Vascular Factors and Prevalence of Mild Cognitive Impairment in Late-Life in Mexico

Rentería

Manly

Vonk

et al. 2021

J Int Neuropsychol Soc

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Objective: To estimate the prevalence of mild cognitive impairment (MCI) and its subtypes and investigate the impact of midlife cardiovascular risk factors on late-life MCI among the aging Mexican population. Method: Analyses included a sample of non-demented adults over the age of 55 living in both urban and rural areas of Mexico (N = 1807). MCI diagnosis was assigned based on a comprehensive cognitive assessment assessing the domains of memory, executive functioning, language, and visuospatial ability. The normative sample was selected by means of the robust norms approach. Cognitive impairment was defined by a 1.5-SD cut-off per cognitive domain using normative corrections for age, years of education, and sex. Risk factors included age, education, sex, rurality, depression, insurance status, workforce status, hypertension, diabetes, stroke, and heart disease. Results: The prevalence of amnestic MCI was 5.9%. Other MCI subtypes ranged from 4.2% to 7.7%. MCI with and without memory impairment was associated with older age (OR = 1.01 [1.01, 1.05]; OR = 1.03 [1.01, 1.04], respectively) and residing in rural areas (OR = 1.49 [1.08, 2.06]; OR = 1.35 [1.03, 1.77], respectively). Depression (OR = 1.07 [1.02, 1.12]), diabetes (OR = 1.37 [1.03, 1.82]), and years of education (OR = 0.94 [0.91, 0.97]) were associated with MCI without memory impairment. Midlife CVD increased the odds of MCI in late-life (OR = 1.76 [1.19, 2.59], which was driven by both midlife hypertension and diabetes (OR = 1.70 [1.18, 2.44]; OR = 1.88 [1.19, 2.97], respectively). Conclusions: Older age, depression, low education, rurality, and midlife hypertension and diabetes were associated with higher risk of late-life MCI among older adults in Mexico. Our findings suggest that the causes of cognitive impairment are multifactorial and vary by MCI subtype.

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Differences in the measurement of cognition for the assessment of dementia across geographic contexts: Recommendations for cross‐national research

Nichols

Deal

Langa

et al. 2022

Alzheimer's & Dementia

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BackgroundAlthough 71% of individuals with dementia are projected to live and low‐ and middle‐income countries by 2050, most dementia research to‐date has been conducted in high‐income countries. Cross‐national studies are needed to understand how the causes and consequences of dementia may differ by country. However, factors such as urbanicity, language of administration or race/ethnicity, which vary across countries, affect the measurement of cognition. A better understanding of which cognitive items perform well across countries or within specific countries will allow researchers to optimize dementia measurement in future cross‐national and international studies.MethodWe used data from the Harmonized Cognitive Assessment Protocol surveys in the US, Mexico, India, England, and South Africa (combined N = 11,364). To define cognitive impairment consistently across countries, we compared participants’ cognitive performance with robust neuropsychological norms within each country. For each HCAP country, we assessed item performance by estimating associations between each cognitive item and cognitive impairment using logistic regression models, controlling for age and gender. We avoided circularity in the analysis by using an iterative quasi‐leave‐one‐out approach. We compared patterns of associations across countries using median odds ratios, and visually, using heatmaps.ResultThe associations between cognitive items and cognitive impairment were stronger in the US (Median Odds Ratio [OR] = 0.17) and England (Median OR = 0.19), in comparison to South Africa (Median OR = 0.23), India (Median OR = 0.29), and Mexico (Median OR = 0.28). Memory items, notably delayed recall tasks, had the most consistent associations of the largest magnitudes across countries. In comparison, there was variability in performance between settings for many language items (e.g. naming a hammer). Items requiring numeracy, including the Trail‐making test, did not perform well in countries with low educational attainment.ConclusionThe performance of cognitive items for the classification of cognitive impairment was not consistent across countries. Although items performing well in a single country could be used to improve measurement precision in specific settings, transporting items between countries without prior validation warrants caution. However, we did identify items that performed well across a range of countries (i.e. delayed recall, animal naming); these items may be of particular utility in future cross‐national research.

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The Mexican Cognitive Aging Ancillary Study (Mex-Cog): Study Design and Methods

Cited by 23 publications

References 34 publications

Solid cooking fuel use and cognitive decline among older Mexican adults

Solid cooking fuel use and cognitive decline among older Mexican adults

Midlife Vascular Factors and Prevalence of Mild Cognitive Impairment in Late-Life in Mexico

Differences in the measurement of cognition for the assessment of dementia across geographic contexts: Recommendations for cross‐national research

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