The compounding burden of disability in Mexico: social protection gaps, chronic disease excess, and prospective mortality from national open data sources

BACKGROUND: Persons with disabilities (PWD) face disproportionate barriers to social protection and healthcare worldwide, yet comprehensive multi-source evidence linking social security coverage, morbidity, and mortality outcomes remains scarce in Latin America. METHODS: We conducted a cross-sectional, multi-source population-based study with a prospective cohort component, integrating nine nationally representative Mexican data sources (2017-2023) encompassing over 125 million persons. Disability was operationalized using source-specific measures, including Washington Group-based instruments where available. We examined social security coverage disparities, catastrophic health expenditure, chronic disease prevalence, intersectional exclusion, prospective three-year mortality, and geographic overlap with healthcare infrastructure deficits. Survey-weighted logistic regression with progressive adjustment, Benjamini-Hochberg correction for multiple comparisons, and unweighted binomial models for prospective mortality were employed. RESULTS: Among 6.8 million PWD in the 2020 Census, apparent social security coverage advantages reflected a structural shift to non-contributory programs driven by older age structure; after demographic adjustment the advantage disappeared (OR = 0.99, p = 0.30), with a modest residual protective effect after full adjustment (OR = 0.92, p < 0.001). Disability compounded exclusion for women (interaction OR = 1.07) and indigenous persons (interaction OR = 1.10; both p < 0.001). Catastrophic health expenditure was higher among PWD households (adjusted OR = 2.02). Disease prevalence was significantly higher across all nine conditions assessed (adjusted ORs ranging from 1.46 for diabetes to 2.92 for depressive symptomatology), with less than 5% attenuation after adjustment. Prospective three-year mortality was elevated (adjusted OR = 3.77; 95% CI: 3.02-4.70; risk ratio 3.0), with a severity gradient reaching OR = 7.24. Non-contributory coverage was not associated with lower mortality (OR = 0.89, p = 0.32). Geographic analysis ecologically estimated approximately 502,858 triple-vulnerable PWD concentrated in high-marginalization states. CONCLUSIONS: The apparent social security advantage of PWD is an artifact of older age structure and a shift toward non-contributory programs that confer nominal affiliation without a detectable mortality benefit in this older-adult cohort, with disadvantage intensifying for indigenous women with disability. Expanding enrollment alone is likely insufficient: closing this gap requires disability-inclusive coverage that translates affiliation into effective protection.