Abstract
Low- and middle-income countries (LMICs) have received substantial amounts of Official Development Assistance for Health (DAH) to address domestic health funding gaps and improve access to universal healthcare. However, the effectiveness of DAH in improving health outcomes remains contested, with varying findings across studies due to differences in methodologies, data sources, and target populations. This systematic review synthesizes the existing evidence on the impact of DAH on health outcomes in LMICs, highlighting both the positive and negative effects, and identifying key mechanisms through which aid influences health. A total of 61 studies were included in the review, with a primary focus on maternal and child health outcomes. Despite methodological differences, the weight of evidence indicates a generally positive impact of DAH, particularly in countries with higher governance standards and better economic conditions. Our findings underscore the importance of contextual factors, such as governance and proximity to aid-funded projects, in shaping the effectiveness of health aid. To maximize the impact of DAH, policymakers need to strengthen donor coordination, align aid with national health priorities, and reinforce domestic health systems. Future research should focus on refining causal inference methods and exploring innovative aid-delivery mechanisms to sustain long-term health improvements.