SA·NT DataLink, a collaboration between the governments of the Northern Territory and South Australia, provides a data linkage service to support research, policy development, service planning and evaluation. The service uses public sector data, suitably de-identified, to allow policy makers to make decisions based on real data. As the Web site states:

De-identified data that are linked for the entire population are not only more inclusive, representative, and unbiased, but also are much more cost effective and efficient than conventional studies based on samples.

The site has a good animation to show how data linkage works. The Australian Institute of Health and Welfare also explains this kind of data integration.