Evaluability assessment as a design tool for complex health interventions: Insights from an EU-project on vaccine hesitancy.

backgroundEvaluability assessment (EA), conducted independently or as part of a broader evaluation process, is performed to determine whether a program, policy, or intervention is ready and suitable for evaluation. This study explores the innovative application of EA as a design-stage tool for guiding complex health interventions. It focuses on the VAX-TRUST - Addressing Vaccine Hesitancy in Europe project, where EA was employed to design and refine interventions addressing vaccine hesitancy across seven European regions.

methodsEA was applied in a qualitative approach using an evaluability checklist. This tool facilitated iterative improvements in intervention design, implementation planning, and evaluation readiness, ensuring interventions were robust and contextually relevant. Additionally, efforts were made to qualitatively measure the impact of the evaluability assessment through an evaluability impact matrix. RESULTS AND DISCUSSION: EA significantly influenced intervention design by identifying gaps and guiding real-time adjustments. Six of the seven interventions were successfully implemented with enhanced planning for unforeseen events, showcasing the iterative benefits of EA in the design phase. The iterative nature of EA allowed for real-time adjustments that enhanced program robustness and adaptability. Insights into the checklist's gaps, such as underdeveloped resource allocation metrics, are discussed to improve future applications.

conclusionsThis work advances EA literature by demonstrating its utility in the design stage and, by reinforcing the early alignment of different components and multiple contexts, provides a replicable framework for planning complex health interventions. Future evaluators are encouraged to adopt this proactive approach for more effective public health strategies.