The WA Data Linkage System - a Powerful Tool for Research, Policy Development and Evaluation

The WA Data Linkage System (WADLS) is built on the concept of a dynamic linked chain of health events, ordered by date. Each linked chain can be broken at any point and new links can be inserted or existing links deleted as new information becomes available. Chains can be extended further into the future or the past as new health events are discovered. Population-based health data linkage systems also exist in Canada (Manitoba, British Columbia) and the United Kingdom (England, Scotland). The WADLS holds a web of links within and between WA's statistical health data collections and is capable of connecting external datasets. The growth in the scope and scale of the linkage system has been steady. The system design differs from the systems operating in Canada and the UK in that it is dynamic and ongoing. The existence of an electronic history of the activity on the system also means that changes over time can be reviewed and analysed. For this paper, the factors associated with the change in scope, scale and quality of the system will be analysed. Alongside these inputs to the system we will present the outputs measured by improvements in the quality of the input datasets, the quantum of extracts of linked data for research projects and the community benefit through publication of research findings, policy changes and improvement to clinical practice. Measurable return on investment to the state economy through awarding of contracts, research grants, scholarships and other funding will also be provided.