A realist synthesis of the implementation of digital health strategies for enhanced health outcomes in Sub-Saharan Africa

• This realist synthesis identifies how and why DH implementation succeeds or fails in Sub-Saharan Context. • The review defines seven interconnected Context-Mechanism-Outcome (CMO) configurations. • Proposes a 3-part conceptual framework: Foundational, Enabling, and Adaptive mechanisms. • Shows technical enablers fail without foundational governance and legal trust. Many sub-Saharan African (SSA) countries have developed national Digital Health (DH) strategies. However, there is significant variability in how these strategies are implemented across different regions, especially in resource-constrained settings. This paper conducts a realist synthesis to explain how, for whom , and under what conditions the implementation of DH strategies facilitates sustainable and equitable health outcomes in SSA. A realist review of 30 articles (2014-2025) from Scopus, Google Scholar, and PubMed was conducted. Using Context-Mechanism-Outcome configurations, the analysis identified the underlying causal mechanisms necessary for effective implementation. The synthesis refined seven interconnected programme theories, clustered into three functional categories. 1) Foundational enabling conditions encompassing coordinated governance, strategic institutionalization, and a legal trust framework to establish legitimacy and safety. 2) Technical and human enablers encompassing infrastructure reliability and socio-technical capability-building with peer validation to create operational capacity. 3) Adaptive mechanisms encompassing participatory co-design and evidence-informed adaptation to ensure contextual fit and sustainable evolution. This review suggests that effective, sustainable, and equitable integration of DH is not achieved through isolated interventions, but through a synergistic ecosystem of seven interconnected mechanisms. By reframing the challenge for policymakers and implementers from asking what technology should be deployed to which foundational, enabling, and adaptive mechanisms must be activated for success, the review offers a critical shift in perspective that advances both policy and practice.