Reimagining Data for Equity: Reaching the Unreached Map Explorer for Localized Public Health Intelligence in the Western Pacific Region.

Geographic information systems (GISs) and digital dashboards have become central to epidemic monitoring and crisis response, yet their broader potential for routine, equity-focused public health decision-making remains underused. As health systems increasingly prioritize reaching underserved and vulnerable populations, mapping platforms must evolve from static visualization tools to dynamic decision-support systems. This paper reflects on the development and strategic role of the Reaching the Unreached (RTU) map explorer, a regional geospatial decision-intelligence platform developed in collaboration with the World Health Organization Regional Office for the Western Pacific. The RTU map explorer integrates high-resolution subnational data across 36 countries and areas in the Western Pacific Region. It consolidates demographic, socioeconomic, health access, and vulnerability indicators into a unified geoportal that enables visualization at resolutions ranging from the national level to the village level. Drawing on open-access spatial repositories and modeled datasets, the platform applies population-based spatial clustering methods to settings where administrative units are too large to capture meaningful local variation. Built using an open-source architecture, the platform offers interactive functionalities, including layer activation, filtering, prioritization tools, and location-specific mapping, to support localized planning and resource allocation. By combining contextual and health-related data within a single interface, the RTU map explorer facilitates a shift from reactive surveillance to proactive, equity-oriented decision-making. Policymakers can compare vulnerabilities across regions, program managers can prioritize high-need districts or communities, and local implementers can identify specific locations for targeted interventions. Although challenges remain, including data recency, modeled data uncertainty, and the need for field validation, the platform illustrates how integrated geospatial intelligence can move public health beyond documenting disparities to actively addressing them through localized, data-driven action.