Key Points:
- The application of geographic information systems (GIS) to public health practice has great potential for improving our understanding of the ecology and causes of complex health issues, and for guiding the design and evaluation of effective population based programs and strategies.
- GIS can summarize vast amounts of tabular data into compelling visual maps that can provide powerful insights and engage the attention of policy makers and the public.
- There are significant methodological issues which must be addressed in order to ensure that map outputs are interpretable and not misleading. The most important of these is dealing with the small number problem which occurs when cases and their associated denominators are sub-divided into many small geographic areas which frequently result is in significant rate instability.
- Although the creation of maps is an important step in public health mapping, it is critical for practitioners to move beyond simple data visualization to an exploration of the statistical characteristics of spatial patterns and to formalized modeling of the relationship between predictor and outcome variables.
- The implementation of GIS in a public health context can be a resource intensive activity, requiring a significant investment.
