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Latest version of Access to Health Assets and Hazards (AHAH) released

The Consumer Data Research Centre and Geographic Data Science Lab are proud to announce the latest release of their data resource, “Access to Healthy Assets and Hazards” (AHAH).

AHAH is a multi-dimensional index for Great Britain measuring how “healthy” neighbourhoods are based on the locations of services that are ‘assets’ or ‘hazards’ for health in each area.

AHAH is calculated based on data from 15 indicators divided into four domains:

  • Retail environment – fast food outlets, pubs, off-licences, tobacconists, gambling outlets
  • Health services – GPs, hospitals, pharmacies, dentists, leisure services
  • Air quality – air pollution levels for Nitrogen Dioxide, Sulphur Dioxide and Particulate Matter (PM10)
  • Natural environment – green spaces and blue spaces

The resource allows researchers and policy makers to understand which areas have poor environments for health and helps to move away from treating features of the environment in isolation to provide a comprehensive measure of neighbourhood quality.

AHAH is produced for Lower Super Output Areas for England and Wales, and Data Zones for Scotland. Component inputs for this index use data that is the most up-to-date as of March 2022.

All of the individual indicators to AHAH have also been made freely available in the data resource in a push for opening up small area health data. As such, it provides one of the most comprehensive free data resource available for such data. You can freely explore how your local area compares on our data at https://mapmaker.cdrc.ac.uk/#/access-healthy-assets-hazards. AHAH and all of the individual indicators are openly available at https://data.cdrc.ac.uk/dataset/access-healthy-assets-hazards-ahah.

Changes from previous versions

The latest version of AHAH includes several methodological and conceptual refinements following extensive public feedback on previous versions.

Most noticeable is the change in how we measure accessibility to green spaces. We received a lot of user feedback, especially from rural communities, who did not feel that measuring distance to nearest accessible park or green space was the best measure since it under-represented rural areas (i.e., farmland that is green but not necessarily accessible).

In response, we have updated the measure to use a satellite derived measure of the total green space (NDVI). We note here the measure is for the resident population and their surrounding contexts.

This has improved the accuracy for measuring access to overall green space. These changes have resulted in changes in the overall AHAH index value, mostly seeing rural areas with good access to green spaces having better overall scores. As a result, we would suggest caution in making comparisons over time between the overall AHAH index.

We have also further updated our statistical approaches to give more accurate accessibility estimates and utilize GPU support for faster processing.

All code for reproducing AHAH can be found here.