Executive Summary

Health system maps provide a visual overview of the level of access to health care. Quantifying access to healthcare however remains a challenge owing to the absence of centralized and authoritative data on health facilities, administrative/health boundary data and population estimates. Where such data exists, these are siloed within health and humanitarian sector actors because of restricted data sharing policies, thus creating inconsistencies in the global geospatial health data ecosystem. Health catchment areas are minimum baseline spatial data used by stakeholders in the health cluster. In this guide of best practices, case studies from different health and humanitarian organizations have been explored and key health geospatial data experts interviewed to understand the methods and policies guiding the creation and use of health catchment area geospatial databases. These data sources and methods have been summarized to provide a clear guideline that informs future initiatives and collaborations aiming to create such databases to fit their organizational goals or contexts.

Health boundary databases are important to understand where people come from and how they access health facilities or healthcare services. In most cases, administrative boundaries serve as designated health boundaries. The mapping of these boundaries and subsequent endorsement by government agencies is what remains to be achieved. Two main approaches – top-to-bottom and bottom-to-top - have been explored in mapping health boundary data, although an intersection of these two methodologies is the ideal being explored. The most reliable populations estimate for health catchment areas is an up-to-date census. However, modelling estimates and micro-censuses can be utilized in situations where census data is not available. A complete and comprehensive list of health facilities is key to the mapping of health catchment areas, and these should ideally be endorsed and maintained by dedicated government agencies in each country. OpenStreetMap, the Common Geo-Registry and the Humanitarian Data Exchange have been identified as popular sources of data for both master and non- master lists of health facilities. In situations where government mandated lists are non-existent, non- mandated lists and boundaries are used to guide programmes and to inform the creation of a master list of health facilities endorsed by a government.

Central governments and government agencies play a key role in data validation, although more granularity is achieved when community health workers and district health teams are involved, as this creates a sense of ownership for the data. The utility of health catchment area databases depends entirely on its accessibility by health actors. Data licensing and data sharing policies that prioritise open access are the substrate with which these databases can be decentralized. Use cases and user stories demonstrate the immense benefit of sharing and utilizing these catchment area databases. However, several challenges facing this process of mapping health boundaries remain to be addressed. The establishment of a national spatial data institute for instance has been proposed as an institutional framework that maximises use and reduces redundancy in this process.

Health catchment areas are not new, they have just not been properly documented, endorsed, shared, and integrated into the work of health and humanitarian actors. Although the WHO could potentially play a coordinating role in creating these centralized databases, partner agencies and organizations need to play their part by reviewing data sharing policies ahead of forming collaborations such as the health catchment area working group. This best practice guide is the first in a series of steps to provide documented guidance and streamline policies that inform a collaborative approach to creating and distributing health catchment area geospatial databases in all health and humanitarian contexts.