Cash transfer programs have differential effects on health: A review of the literature from low and middle-income countries

Abstract Background Cash transfer programs have grown increasingly popular and are now used as interventions to target a wide array of health outcomes across many diverse settings. However, cash transfer experiments have yielded mixed results, highlighting gaps in our understanding of how these programs work. In particular, we do not yet know whether cash transfers are more effective for certain health outcomes compared to others, or are more effective for some population subgroups compared to others. Here, we ask whether the effects of cash transfers on health outcomes differ across study subgroups. Methods We reviewed the literature on cash transfer experiments conducted in low and middle income countries, published in English between 1985 and 2015. We documented whether the investigators reported either i) stratum-specific estimates or ii) the interaction term between subgroups and exposure to the intervention. For studies that presented stratum-specific estimates without statistical tests for heterogeneity, we assessed heterogeneity across subgroups with a Cochran Q test. Results Of the 56 studies we reviewed, 40 reported effects on study subgroups. The majority of the cash transfer interventions had different magnitudes of effects on health across subgroups. This heterogeneity was often underreported or not formally analyzed. We find substantial heterogeneity of cash transfers on child health and on adult health yet little heterogeneity of cash transfers on sexual and reproductive health. Conclusions Accounting for the heterogeneous impacts of cash transfers during program design and evaluation is necessary to better target cash transfer programs and generate more precise data on their effects.