Quality Assurance in Practice: Insights from a Cluster Randomized Control Trial Evaluating a novel Spatial Repellent vector control intervention in Kenya

The implementation of quality assurance (QA) systems is crucial for generating reliable evidence in large-scale vector control trials. This paper documents the QA framework developed for the Advancing Evidence for the Global Implementation of Spatial Repellents (AEGIS) program in Busia, Kenya. The trial encompassed 60 clusters at baseline dropping to 58 during the intervention phase and followed 5,717 participants from three cohorts spanning two and a half years. Key QA innovations included a slot and sync scheduling system that significantly enhanced participant screening completion rates, scannable health facility registers for adverse event monitoring, electronic systems for managing microscopy samples and investigational products (IP), integration of community engagement in quality processes, and adaptation of procedures during COVID-19. We present the methods, challenges, and solutions in maintaining trial quality throughout the study period, providing valuable insights for future vector control studies in similar settings. Our experience demonstrates that robust QA implementation in resource-limited settings requires adaptable systems, continuous monitoring, a strong community partnership and strong financial support for development and implementation of QA systems.