Sociodemographic inequalities in functional dependency among older adults: Cross-sectional evidence from 35 countries.

BACKGROUND: Functional dependency is a key marker of loss of independence in older age, but comparable evidence on its prevalence and sociodemographic inequalities across countries remains limited. OBJECTIVE: To estimate the prevalence of functional dependency across severity levels, compare prevalence across countries and World Bank income groups, and quantify absolute and relative sociodemographic inequalities within individual countries. METHODS: A cross-sectional analysis of pooled, individual-level data from nine nationally representative surveys was conducted for older adults in 35 lower-middle-, upper-middle-, and high-income countries. Three dependency levels were defined based on activities of daily living and instrumental activities of daily living. The age-standardized prevalence of these three levels was estimated by country, World Bank per capita income category, and sociodemographic characteristics. Logistic regression models and marginal standardization were used to estimate adjusted prevalence ratios and average marginal effects, representing relative and absolute differences in predicted prevalence, respectively. RESULTS: The final sample included 121,201 adults aged 60 years or older. The age-standardized prevalence of level 1, level 2, and level 3 dependency was 19.9% (95% CI 19.4-20.4), 25.7% (25.1-26.2), and 32.6% (32.0-33.1), respectively. Differences across income groups generally became more pronounced at broader dependency thresholds. For level 3 dependency, prevalence was 44.7% (44.0%-45.3%) in lower-middle-income countries, 35.0% (34.0%-36.1%) in upper-middle-income countries, and 20.0% (19.5%-20.5%) in high-income countries. Level 3 dependency ranged from 9.2% in Malta to 44.5% in India. Absolute and relative inequalities varied substantially across countries, with the most pronounced disparities generally observed by age and educational attainment. CONCLUSIONS: Functional dependency was common but varied across countries and population groups. These estimates provide cross-national benchmarks and can inform country-specific long-term care planning for disadvantaged groups.