INTRODUCTION:
Multimorbidity is an increasing public health concern in low- and middle-income countries (LMICs), with important implications for health equity and the sustainability of health systems.¹ As countries in the Global South experience rapid population ageing, understanding temporal trends in multimorbidity is critical for inclusive health planning.² This study examined trends in the prevalence of multimorbidity and its socio-demographic correlates among older adults in India and South Africa between 2007 and 2015.

METHODS:
We used nationally representative data from the World Health Organization’s Study on Global AGEing and Adult Health (SAGE), collected in 2007 (Wave 1) and 2014/2015 (Wave 2). The analysis included adults aged ≥50 years (India: n=7,150 in Wave 1 and n=7,110 in Wave 2; South Africa: n=3,565 in Wave 1 and n=2,163 in Wave 2). We estimated weighted prevalence of multimorbidity at each time point and assessed changes over time. Socioeconomic correlates of multimorbidity were examined.

RESULTS:
The prevalence of multimorbidity increased over time in both countries. In India, prevalence rose significantly from 26.4% (95% CI: 25.4–27.5) in 2007 to 29.2% (95% CI: 28.2–30.3) in 2014/15 (p<0.001). In South Africa, multimorbidity increased from 27.4% (95% CI: 22.2–33.2) to 30.2% (95% CI: 25.4–35.4), although this change was not statistically significant. Across all survey waves, multimorbidity was consistently more prevalent among individuals in higher wealth quintiles, highlighting complex patterns of social inequality in disease burden.

CONCLUSIONS:
Multimorbidity is increasing over time among older adults in two Global South countries, underscoring the growing burden of chronic conditions in ageing populations. These findings highlight the need for equitable and sustainable health system responses that address multimorbidity across diverse socioeconomic groups and support inclusive planning for ageing societies in LMICs.