Child support grant expansion and cognitive function among women in rural South Africa: Findings from a natural experiment in the HAALSI cohort

Background Cash transfers are a promising but understudied intervention that may protect cognitive function in adults. Although South Africa has a rapidly ageing population, little is known about the nature of association between cash transfers and cognitive function in this setting. Objectives We leveraged age-eligibility expansions to South Africa’s Child Support Grant (CSG) to investigate the association between duration of CSG eligibility and cognitive function of biological mothers of child beneficiaries in South Africa. Methods We analysed 2014/2015 baseline data from 944 women, aged 40–59 years with at least one CSG-eligible child, enrolled in the population-representative HAALSI cohort in Agincourt, South Africa. Duration of CSG eligibility for each mother was calculated based on the birth dates of all their children and the CSG age-eligibility expansion years (2003–2012). Cognitive function was measured using a cognitive battery administered at the HAALSI baseline interview. Linear regression was used to estimate the association between duration of CSG eligibility, dichotomized as low (≤10 years) and high (>10 years) eligibility, and cognitive function z-scores of the mothers. Results High vs. low duration of CSG eligibility, was associated with higher cognitive function z-scores in the full sample β: 0.15 SD units; 95% CI: 0.04, 0.26; p-value = 0.01. In mothers with one to four lifetime children, but not five or more, high vs. low duration of CSG eligibility, was associated with higher cognitive function z-scores β: 0.19 SD units; 95% CI: 0.05, 0.34, p-value = 0.02. Conclusion Government cash transfers given to support raising children may confer substantial protective effects on the subsequent cognitive function of mothers. Further studies are needed to understand how parity may influence this relationship. Our findings bring evidence to policymakers for designing income supplementation programmes to promote healthy cognitive ageing in low-income settings.