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Partner Profiles: Small Area Health Statistics Unit of Imperial College London (SAHSU)

Organizational Mission/Goals

The main aim of Imperial College of London’s Small Area Health Statistics Unit (SAHSU) has been to assess the risk posed by environmental factors to the health of the population, with an emphasis on the use and interpretation of routine health statistics.


SAHSU was established in 1987, following a recommendation of an enquiry headed by Sir Douglas Black into the incidence of leukemia in children and young adults near the Sellafield nuclear plant in Cumbria, UK. Substantial efforts continue to maintain and develop the SAHSU databases and to further develop spatial analysis methods. Reports of potentially raised rates of disease around environmental sources or in specific areas can cause great public anxiety and need to be handled efficiently and effectively by the authorities concerned. A common part of the response to such reports is to use routinely collected statistics to establish whether rates of the disease are higher than would be expected for the population at risk on the basis of a reference set of rates.

SAHSU developed the UK Rapid Inquiry Facility (RIF) to speed up this resource-intensive part of the investigation process. RIF can rapidly generate rates and relative risks for any given health outcome, for specified age and year ranges, for any given geographical area. It also produces unsmoothed and smoothed maps of relative risks, together with maps showing the demographic, socio-economic, environmental, and geographical characteristics of the area. RIF’s functionality holds great promise for use in a wide variety of projects that involve evaluating the spatial and temporal relationships between environmentally related diseases and environmental hazards.

SAHSU has collaborated with seven European Union partners to further enhance the utility of the RIF. The European Health and Environment Information System for Exposure and Disease Mapping and Risk Assessment (EUROHEIS) project was funded by the European Commission, Directorate-General Health and Consumer Protection, Luxembourg, under a program of action on pollution-related diseases. It was constructed as a 3-year program, made up of a feasibility study in year one (2000), an implementation phase in year two (2001–02), and an evaluation phase in year three (2002–03). EUROHEIS collaborators demonstrated the usefulness of RIF in answering questions concerning environmental health risks, improving public health through use of the system, preventing human illness and diseases, and obviating sources of danger to health. This was demonstrated through a series of case studies carried out within each of the partner countries. The effects of socio-economic factors were incorporated in the analyses, which evaluated the use of the systems for environmental health impact assessment.

Partnership Activities with Centers for Disease Control and Prevention (CDC)

CDC, the Imperial College, and the Utah Department of Health are collaborating on adapting and enhancing the Imperial College’s RIF software for use in CDC’s National Environmental Public Health Tracking Network.

The goal of this project is to increase the functionality and versatility of the RIF for use in evaluating temporal and spatial relationships between disease and environmental hazards in the National EPHT Network. To do so, SAHSU is carrying out the following activities:

  1. Evaluating country-specific data issues and modifying RIF to account for these differences
  2. Enhancing RIF software to be more user-friendly and flexible (e.g. enhanced user interfaces; database management system independent; allowing input of exposure modeling data; and enhanced output features for further analysis or report writing.)
  3. Conducting simulation studies to assess the tool
  4. Working with the State of Utah, one of the Tracking Program funded partner states, to initially test the revised RIF software on a study of contaminated groundwater and cancer
  5. Developing guidelines to facilitate the use of the RIF for environmental public health tracking
  6. Developing a comprehensive RIF training course

For more information on SAHSU, visit: [external link]

For more information on EUROHEIS, visit: [external link]

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