The impact of a randomized cash transfer intervention on mortality of adult household members in rural South Africa, 2011-2022.

Background: Increasing socioeconomic resources through cash transfer payments could help promote healthy longevity. However, research in this area is limited due to endogeneity in cash transfer exposures and limited geographic representation.

Methods: We leveraged the HPTN 068 randomized cash transfer trial, conducted from 2011 to 2015 in a rural setting in South Africa. We assessed long-term mortality follow-up (until March 2022) on older adult members (n = 3568) of households enrolled in the trial from the complete Agincourt Health and socio-Demographic Surveillance System census of the underlying source population. The trial intervention was a monthly cash payment of 300 Rand conditional on school enrollment of index young women. The payments were split between the young woman (1/3) and their caregiver (2/3). Young women and their households were randomized 1:1 to intervention vs. control. We used Cox PH models to compare mortality rates in older adults living in intervention vs. control households.

Findings: The cash transfer intervention did not significantly impact mortality in the full sample [HR (95% CI): 0.94 (0.80, 1.10)]. However, we observed strong protective effects of the cash transfer intervention among those with above-median household assets [HR (95% CI): 0.66 (0.50, 0.86)] and higher educational attainment [HR (95% CI): 0.37 (0.15, 0.93)].

Interpretation: Our findings indicate that short-term cash transfers can lead to reduced mortality in certain subgroups of older adults with higher baseline socioeconomic status. Future work should focus on understanding the optimal timing, structure, and targets to maximize the benefits of cash transfer programs in promoting healthy aging and longevity.