Data Composition

The operational boundary of a health catchment area is the lowest boundary classification of health geospatial data. Health boundary data are necessary to answer three key questions:

(i) Where do people live?

(ii) How do they reach health facilities? and

(iii) How many people are served by health facilities? (Source: Key Informant Interview).

The centre of the health catchment area in most cases is the health facility, while additional data on villages or communities served by these health facilities as well as the population distribution of these communities provide the essential building blocks for creating meaningful health catchment area databases. The collection of data on each of these key building blocks is the most challenging part of the process, and where such data exist, these are siloed within organizations, data components are inconsistent and, in most cases, not endorsed by a country’s Ministry of Health or other government agency. In this section, I will attempt to discuss some strategies that have been employed by international health and humanitarian organizations to collect each of these data components. Before I proceed, it is worth mentioning that geospatial data can be captured in four essential components:9

1. Objects with a fixed location identified by a point (e.g health facilities, communities)

2. Objects with a fixed location but identified by polygons or lines (e.g administrative boundaries, rivers)

3. Objects which although mobile, are geographically represented as being attached to a fixed object (e.g pregnant women in a community)

4. Elements of the environment that are distributed spatially (e.g terrain, land surface attributes)