BACKGROUND: Maintaining functional capacity and social participation is essential for healthy ageing, yet the association between socioeconomic status (SES) and these outcomes across diverse global contexts remains inadequately quantified. METHODS: This cross-sectional analysis used harmonised individual-level data from eight longitudinal ageing studies across 22 countries in adults aged ≥ 60 years (n = 70 189). A composite SES index was derived from education and household wealth. Associations between SES and three ICF-based outcomes (muscle strength, physical performance, and community participation) were assessed using multilevel mixed-effects logistic regression to account for the nested structure of the data. RESULTS: Among 70 189 participants (median age 68 years IQR 63-74; 50.9% female), strong inverse socioeconomic gradients were observed across all outcomes. Compared with the highest SES group, the lowest SES group had significantly increased odds of low muscle strength (adjusted odds ratio aOR, 1.92; 95% CI, 1.81-2.03), poor physical performance (aOR, 1.78; 95% CI, 1.44-2.20), and low community participation (aOR, 3.91; 95% CI, 3.07-4.75; P < 0.001 for trend for all). The odds of co-occurring impairments were substantially elevated under low SES conditions, most notably for simultaneous impairment in all three domains (aOR, 9.78; 95% CI, 8.29-11.53; P < 0.001). Socioeconomic gradients varied by country income level, being most pronounced for muscle strength in low-income countries, physical performance in middle-income countries, and community participation in high-income countries. CONCLUSIONS: SES is a fundamental determinant of healthy ageing, shaping outcomes across muscle strength, physical performance, and community participation. These findings highlight measurable SES disparities in functional capacity across diverse global contexts and provide a robust evidence base for equity-focused interventions to reduce ageing-related functional decline.
Talifu et al. (2026) studied this question.