Software & mapping
The Geographical variations product suite uses geographical information software (GIS) developed by the Environmental System Research Institute (Esri). Products were constructed and published from ArcGIS Online, a cloud-based Esri environment. This platform provides a variety of web applications allowing users to explore, analyse, monitor and visualise geographical data. ArcGIS Online software updates occur periodically through the year.
This product utilised ArcOnline to develop a number of maps and dashboards, accessible from the AIHW website under the disease topic page.
For more information on ArcGIS Online.
Disease dashboards were constructed in Operations Dashboard (by Esri), a configurable web app that provides real-time operational views of people, services, assets and events data. Dashboards may contain multiple interactive elements such as maps, charts, imagery and dynamic text within a single interactive page. Dashboards offer a comprehensive and engaging view of the data to provide key insights for at-a-glance decision making.
For more information on Esri Operations Dashboard.
Disease impact maps
Maps form a component of the ArcGIS Online dashboard to represent the geographical variation of disease impact measures. These measures include prevalence, death and hospitalisation mapped to 3 geographic levels— state/territory; Primary Health Network (PHN); and Population Health Area (PHA) and include:
- crude rate
- age-standardised rate
- rate ratio.
Choropleth maps represent the geographical variation of the disease impact. A sequential colour scheme represents high values (high impact) by darker colours and low values (low impact) by lighter colours. A diverging colour scheme was also used where 2 colour schemes represent the variation of values above or below a threshold (for example, rate ratio maps with a threshold value of 1).
The number of categories used for the variation depended on the data distribution; that is, the range between the minimum and maximum value of the measure. The categories represent area-based quantile ranges of between 3 and 10 groups depending on:
- the number of areas to be classified
- the value ranges of the quantiles
- the spread of the measures (as difference between maximum and minimum).
In most cases, state and territory map legends have 3 categories (tertiles) and PHN and PHA map legends have 5 categories (quintiles). The number of quantiles presented in the legend for the rate ratio map varies in some cases, to allow a better classification between areas with rates above the national average. For example, a quantile category with a range between 1 and 1.20 had to be broken down into smaller groups to allow a better classification of areas with similar rate ratios. This results in rate ratio map legends ranging from 5 to 10 categories. Conversely, for measures with a small spread of values, the number of categories used in the legend has been reduced (e.g., HSVD prevalence) as there was not great variation in the measure by geography.