Multimorbidity Patterns and Functioning Associations Among Adults in a Local South African Setting: A Cross-Sectional Study.

Multimorbidity poses significant challenges for resource-constrained healthcare systems, particularly in low and middle income countries where specific combinations of chronic conditions may differentially impact function. This cross-sectional study examined multimorbidity patterns and associations with functioning among 165 adults attending semi-rural primary healthcare facilities in South Africa. Participants completed performance-based measures (handgrip strength, five-times sit-to-stand test, step test and exercise prescription tool [STEP] maximum oxygen consumption) and self-reported function (12-item WHODAS 2.0). Exploratory factor analysis identified three multimorbidity patterns: HIV-hypercholesterolaemia-obesity (Pattern 1), hypertension-anaemia-lung disease (Pattern 2), and stroke-heart disease-hypercholesterolaemia (Pattern 3). Pattern 1 was associated with reduced aerobic capacity (β = -6.41, 95% CI: -9.45, -3.36) and grip strength (β = -0.11, 95% CI: -0.14, -0.07). Pattern 2 showed associations with mild (β = 1.12, 95% CI: 0.28, 1.97) and moderate (β = 1.48, 95% CI: 0.53, 2.43) self-reported functional problems and reduced grip strength (β = -0.05, 95% CI: -0.09, -0.003). Pattern 3 was associated with all self-reported impairment levels, with the strongest association for severe impairment (β = 2.16, 95% CI: 0.32, 4.01). These findings highlight the convergence of infectious and non-communicable diseases in this setting. Simple clinical measures like grip strength and self-reported function may hold potential as screening or monitoring tools in the presence of disease patterns, warranting further research.