Objective: The aim of this study was to quantify the use of linked data for health and human services research in Australia since the establishment of the Population Health Research Network (PHRN) in 2009. Methods: A systematic literature search was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 checklist to search for all publications involving the use of Australian linked data between 2009–10 and 2016–17. Publications were categorised by subject, data linked and data linkage unit involved. Results: In all, 7153 articles were identified from the initial search, and 1208 were included in the final analysis. An increase in the number of publications involving linked data was observed from 2009–10 through to 2015–16. Most articles (82%) featured data linked by at least one PHRN-funded data linkage unit. The research areas of 86% of publications were able to be classified according to the International Statistical Classification of Diseases and Related Health Problems 10th Revision Australian Modification (ICD-10-AM). The number of publications involving cross-sectoral linked data also increased. Conclusions: Investment in Australian data linkage infrastructure has seen an increase in the number of research publications involving the use of linked health and human services data. This study identified areas where linked data is commonly used and those where use could be improved. What is known about the topic?: Data linkage is a method of bringing together information about individual people, places and events from different sources in a way that protects individual privacy. Individual jurisdictions have reported benefits from research conducted using linked data, including the generation of new knowledge and supporting improvements in the delivery of a wide range of health and human services. There has been significant investment in national data linkage infrastructure in Australia over the past 8 years. To date, there has been no systematic investigation of the effect of this investment on the use of linked population data by the research community. What does this paper add?: This paper provides evidence of the increased use of high-quality population-based linked data in research over the 8-year period studied. It demonstrates the application of data linkage across a wide range of health areas and highlights the small but growing number of studies using cross-sectoral data to investigate complex conditions. What are the implications for practitioners?: It is important to demonstrate to funders, policy makers, data custodians and researchers the value of robust data linkage capacity as an important national resource. Its use by researchers can bring enormous social and economic benefits by providing a more complete picture of the health and well-being of the community. The range of data collections routinely linked is increasing, as is the pool of researchers experienced in handling and analysing the data. Continued investment in Australia’s data linkage infrastructure and the inclusion of other collections including general practice data will augment the use of this infrastructure in expanding the evidence base for policy makers and practitioners.

Population-based data linkage has a long history in Australia from its beginnings in Western Australia in the 1970s to the coordinated national data linkage infrastructure that exists today. This article describes the journey from an idea to a national data linkage network which has impacts on the health and well-being of Australians from preventing developmental anomalies to responding to the COVID-19 pandemic. Many enthusiastic and dedicated people have contributed to Australia’s data linkage capability over the last 50 years. They have managed to overcome a number of challenges including gaining stakeholder and community support; navigating complex legal and ethical environments; establishing cross-jurisdictional collaborations, and gaining ongoing financial support. The future is bright for linked data in Australia as the infrastructure built over the last 50 years provides a firm foundation for further expansion and development, ensuring that Australia’s linked health and human services data continues to be available to address the evolving challenges of the next half century.