A Decade of Data Linkage in Western Australia: Strategic Design, Applications and Benefits of the WA Data Linkage System

Article excerpt

Abstract

Objectives: The report describes the strategic design, steps to full implementation and outcomes achieved by the Western Australian Data Linkage System (WADLS), instigated in 1995 to link up to 40 years of data from over 30 collections for an historical population of 3.7 million. Staged development has seen its expansion, initially from a linkage key to local health data sets, to encompass links to national and local health and welfare data sets, genealogical links and spatial references for mapping applications.

Applications: The WADLS has supported over 400 studies with over 250 journal publications and 35 graduate research degrees. Applications have occurred in health services utilisation and outcomes, aetiologic research, disease surveillance and needs analysis, and in methodologic research.

Benefits: Longitudinal studies have become cheaper and more complete; deletion of duplicate records and correction of data artifacts have enhanced the quality of information assets; data linkage has conserved patient privacy; community machinery necessary for organised responses to health and social problems has been exercised; and the commercial return on research infrastructure investment has exceeded 1000%. Most importantly, there have been unbiased contributions to medical knowledge and identifiable advances in population health arising from the research.

Aust Health Rev 2008: 32(4): 766-777

INFRASTRUCTURE TO ENABLE research has become a major planning focus in many countries, including the United States, Canada, the United Kingdom, members of the European Union and Australia.1 Several countries have undertaken national audits of their stock of research infrastructure, which in the health sector includes biomedical laboratories, imaging equipment, biobanks and supercomputers.1

Concepts about enabling national infrastructure for research on population health and welfare have existed for over half a century. In 1946, Dunn proposed the idea that each person creates a "Book of Life", starting with birth, ending in death and composed of the records of important health and social events.2 Dunn developed the concept of collating the records into a personal file and named the process record linkage. He predicted that statistical analysis of linked records would be useful to health and welfare agencies in evaluating their service programs. He suggested also that linking files of data would establish the accuracy of the source records.2

All of Dunn's predictions have been proven to be correct in theory, albeit in practice comprehensive national systems of linked health and welfare data remain uncommon. Successful implementation demands high levels of community capital and inter-agency cooperation before the many diverse stakeholders will relinquish their immediate interests in favour of a more futuristic and public-spirited common vision. It was not surprising, therefore, that the international review by Roos et al described only a handful of information-rich environments worldwide, which have been constructed from the linkage of multiple, large, population-based, administrative data sets.3 They included the Manitoba Population Health Information System,4 Oxford Record Linkage Study,5 Scottish Record Linkage System,6 Rochester Epidemiology Project,7 the Centre for Health Services and Policy Research in British Columbia,8 and the Western Australian Data Linkage System (WADLS).9

This report describes the strategic design, the steps to full implementation and the outcomes achieved by one of the world's few comprehensive, population-based data linkage systems, the WADLS, which has linked over 30 health data collections for a population of 2.0 million living in the western one-third of the Australian continent. Our report coincides with the tenth anniversary of the WADLS, which was instigated in 1995 and first became fully operational in 1998.

Developmental history

Hobbs'legacy 1970-94

We define data linkage as "the bringing together from two or more different sources, data that relate to the same individual, family, place or event". …