The functional gateway to dementia: Instrumental decline mediates the role of vascular risk on cognition in rural South Africa

Abstract Introduction In rural South Africa, pathways linking vascular risk to cognitive decline remain unclear where biomarker and specialist assessment resources are limited. We examined whether instrumental activities of daily living (IADL) may function as a practical bridge between vascular risk and later memory. Methods Longitudinal Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community dementia sub‐study data from 508 adults (M age = 63.5 years) over 3.7 years were analyzed using network analysis, structural equation modeling, and receiver operating characteristic analysis. Results IADL was the most central network node (strength = 1.79; betweenness = 1.60). Stroke history was not directly associated with follow‐up memory after adjustment (β = −0.24, P = 0.378), but had a significant indirect association through IADL impairment (β = −0.19, P = 0.014). The prediction model showed fair discrimination (area under the curve = 0.74, 95% confidence interval: 0.68–0.79). Discussion IADL surveillance may complement cognitive screening in low‐resource settings, but findings remain observational.