Understanding the Adaptation of Evidence-Based Interventions from a Systems Perspective: Integrating Implementation and Systems Sciences to Guide the Scaling of a Community Health Worker Program

The ‘Health-2-Go’ program is a complex, community-based intervention designed to improve healthcare access and reduce child mortality in rural and hard-to-reach areas of Ghana. This dissertation presents a comprehensive evaluation of the program, divided into three primary aims: assessing the program's impact on health outcomes, characterizing the core components of the intervention and its implementation strategy, and evaluating cost-effectiveness of scaling the program to a full district.Aim 1 investigates the impact of ‘Health-2-Go’ on child mortality and healthcare utilization through a series of regression models. Using retrospective cohort data, obtained through primary data collection, the study finds that communities with access to ‘Health-2-Go’ experience significant reductions in under-five mortality and decreased use of healthcare services for malaria treatment, indicating the program's effectiveness in improving health outcomes.Aim 2 characterizes the core components of the complex intervention and its implementation strategy through semi-structured interviews and qualitative analyses (informed by Systems Science and Implementation Science). The findings highlight critical elements such as quality training, effective supervision, and community engagement, and emphasize the value of a social franchise structure in achieving program success and scalability.Aim 3 evaluates the cost-effectiveness of scaling ‘Health-2-Go’ to a full district using a Markov model. The analysis shows that the program is a financially viable strategy for extending healthcare access, with an estimated annual cost per child significantly lower than alternative pathways. Incremental Cost-Effectiveness Ratios (ICERs) and Probabilistic Sensitivity Analysis (PSA) provide critical insights for informing health policy and resource allocation.The integration of Systems Science and Implementation Science perspectives across these aims offers a holistic understanding of the program’s impact and sustainability. Together, the findings support the scalability of ‘Health-2-Go’ and provide actionable insights for its expansion. Future research should focus on validating these results through larger-scale implementations and exploring optimization strategies to enhance program efficiency and effectiveness.This dissertation contributes to the field of translational research by demonstrating the practical application of integrated research methods to bring evidence-based health programs into sustained community practice, offering broad recommendations for policymakers and practitioners aiming to improve healthcare access and outcomes in underserved populations.