The study draws on ENSANUT 2024, Mexico’s National Health and Nutrition Survey, one of the most methodologically rigorous health surveys in Latin America. The analytical sample included 11,283 adults aged 20 years and older, representing a weighted population of approximately 75.1 million people. Because the survey uses complex probability sampling, the researchers applied survey weights throughout their analysis, allowing their estimates to generalize to the entire adult population of Mexico. Functional limitation was measured with the Washington Group Short Set on Functioning, an internationally standardized instrument that asks respondents about difficulty across six core domains: walking, seeing, hearing, cognition, self-care, and communication. Using this tool places Mexico’s estimates on a comparable footing with disability statistics from countries around the world.

The conceptual heart of the paper is the SHVI itself, built on the Alkire-Foster methodology, the same counting framework that underpins the global Multidimensional Poverty Index used by the United Nations Development Programme. Rather than treating poverty, educational disadvantage, and exclusion from health services as separate problems, the Alkire-Foster approach counts how many deprivations a person experiences simultaneously. The researchers organized the index into three domains: educational deprivation, capturing incomplete schooling; health-system access exclusion, reflecting lack of affiliation to or access to medical services; and socioeconomic position deprivation, capturing material disadvantage. A person was classified as structurally vulnerable if they experienced deprivation in two or more of these domains, following the dual-cutoff logic that defines the Alkire-Foster family of measures.

The headline result is a textbook dose-response gradient. Weighted prevalence of functional limitation across the whole adult population stood at 8.2 percent, but that single number conceals a steep social slope. Among adults with no deprivations on the SHVI, functional limitation affected 5.4 percent. With one deprivation, prevalence climbed; with two, it climbed further; and among adults deprived in all three domains, it reached 14.6 percent—nearly triple the rate seen among the most advantaged. In fully adjusted models controlling for age, sex, and multimorbidity, adults classified as structurally vulnerable faced 75 percent higher odds of functional limitation, and those deprived in all three domains faced more than double the odds relative to those with none.

The age pattern of the association is one of the study’s most technically interesting findings. The SHVI effect was not statistically significant among adults aged 20 to 39 years, but became significant from midlife onward. This suggests that the biological and functional consequences of accumulated structural disadvantage take decades to manifest: younger adults may carry the same deprivations without yet showing measurable limitations in daily functioning, while the wear of poor schooling, material hardship, and blocked healthcare access surfaces in the body during middle and older age. Notably, however, the formal statistical test for interaction between the SHVI and age group did not reach significance, with a p-value of 0.284. The authors are careful on this point: the age-graded pattern is suggestive and consistent with cumulative-disadvantage theory, but the interaction itself was not statistically confirmed in this sample.

Sex differences emerged in a subtler form. The relative gradient—the proportional increase in odds of functional limitation per additional deprivation—was not significantly different between men and women. But because women in the survey started from a higher baseline prevalence of functional limitation, the same relative risk translated into a consistently greater absolute burden. In practical terms, a given level of structural vulnerability removes more functioning from women’s lives in absolute terms than from men’s. This distinction between relative and absolute effects is a recurring theme in health equity research, and the study demonstrates why it matters: policies evaluated only on relative risks can underestimate the differential impact of deprivation on women.

When the researchers decomposed the index, educational deprivation emerged as the strongest individual correlate of functional limitation, retaining its association after adjustment for the other domains and covariates. Health-system access exclusion, by contrast, was not independently significant once other factors were controlled. This asymmetry is analytically revealing. Education shapes health across the entire life course—through employment, income, health literacy, working conditions, and the cognitive reserve that buffers age-related decline—whereas formal affiliation to a health system, while essential, may be a blunter and less discriminating marker of actual healthcare access in a country with a segmented insurance landscape. The finding hints that in Mexico, the long arm of schooling reaches further into late-life functioning than the administrative fact of insurance coverage.

Methodologically, the analysis took care to guard against statistical artifacts. The authors report using generalized variance inflation factors to check for multicollinearity among the deprivation domains and covariates, and they employed likelihood ratio tests to compare nested models. Adjustments for multimorbidity are particularly important, since chronic diseases are a major pathway linking deprivation to disability, and failing to account for them could either inflate or mask the structural effect. The cross-sectional design, however, imposes a firm limit on interpretation: the data capture a single moment in time, so the study can establish association and gradient but not causation or the temporal sequence linking deprivation to limitation. Reverse causation—functional limitation itself worsening educational and economic outcomes—cannot be excluded, and longitudinal designs will be needed to disentangle direction.

The scale of the problem is what gives the findings their policy urgency. One in five adults in the weighted sample—about 21.7 million people—met the definition of structural vulnerability, meaning they were deprived in at least two of the three domains simultaneously. Previous health research in Mexico and other low- and middle-income countries has typically examined educational lag, healthcare exclusion, and material poverty in isolation, which the authors argue systematically misses the compounding effect of co-occurring deprivations. A counting index like the SHVI makes that compounding visible and quantifiable, and because it is built from domains already tracked by national statistical systems such as CONEVAL and INEGI, it can in principle be recalculated each survey cycle and monitored as an equity indicator.

The study’s authors, based at Tecnológico de Monterrey and the Universidad Autónoma de Nuevo León, position the SHVI as a replicable population-level framework for identifying structurally vulnerable groups and guiding intersectoral policy—interventions that span education, social protection, and health systems rather than treating each in a silo. For a country where the epidemiological transition has loaded chronic disease and multimorbidity onto populations still carrying deep structural inequalities, the message of the dose-response curve is stark: the more domains in which a person is deprived, the more likely their body will eventually register the deficit. Functional limitation is not merely a biomedical outcome of aging; on this evidence, it is also the cumulative signature of social arrangements, measurable, gradable, and—potentially—preventable through policy that addresses deprivations together rather than one at a time.

Subject of Research: The association between multidimensional structural deprivation and functional limitation among Mexican adults

Article Title: Structural health vulnerability and functional limitation among Mexican adults: a nationally representative cross-sectional analysis of ENSANUT 2024

Article References: Kaur, P., Singh, J. J., & Argüelles-Pérez, J. M. (2026). Structural health vulnerability and functional limitation among Mexican adults: a nationally representative cross-sectional analysis of ENSANUT 2024. International Journal for Equity in Health. https://doi.org/10.1186/s12939-026-03051-2

Image Credits: AI Generated

DOI: 10.1186/s12939-026-03051-2

Keywords: structural vulnerability, functional limitation, ENSANUT 2024, Alkire-Foster methodology, health equity, social determinants of health, multidimensional deprivation, Mexico, Washington Group Short Set, multimorbidity, educational deprivation, health-system access