Skip to main content
Posted on 07 Apr 2021

Data linkage undertaken by the Centre for Victorian Data Linkage (CVDL) serves many valuable purposes, including measuring patient outcomes for particular medical conditions or treatments; helping understand the needs and clinical/service pathways of particular population groups to design more effective services; and quantifying how increased investment or policy changes in one part of the health system might impact demand in other parts of the system . These are just a handful of aspects that are evident in the CVDL’S work to support Victoria’s COVID-19 response. 

For several years, the CVDL has collaborated with the Department’s Health Protection Branch to produce a linked dataset of notifiable infectious disease data, inpatient hospital admissions, emergency department attendances and deaths. 

In early 2020, as the seriousness of the COVID-19 pandemic became evident, it was agreed to increase the frequency of the linkage from quarterly to daily to assist the public health response.

Increasing the frequency of this linkage presented a number of challenges, including technology limitations, the need to obtain and access the data daily and the time and resources involved in accurately linking millions of records. To address these challenges, the CVDL and Health Protection Branch developed a bespoke linkage infrastructure using highly secure technologies to improve processing power and manage user access and security. Use of the Department’s Common Data Layer allowed the CVDL to automate upload of the required datasets on a daily basis. 

The CVDL also trialled a population linkage spine methodology, where the datasets are linked to a “spine” of high-quality datasets with high population coverage, in this case electoral enrolments, driver’s licence and births datasets. This methodology increased the speed and accuracy of the linkage.

The daily linked dataset was successfully implemented in March 2020. During 2020, it provided a useful source of data for monitoring short-term COVID-19 outcomes. The de-identified research dataset produced by this linkage has many applications for understanding the long-term health impacts of COVID-19. The CVDL is also developing linked datasets to answer research and policy questions about the impact of COVID-19 on the Victorian population and health services usage, across areas including mental health, cancer and chronic health conditions. It would not be possible to answer these questions without the availability of linked data.

For more information about the CVDL, please contact Sharon Williams, Manager of the Centre for Victorian Data Linkage via

Page last updated: 07 Apr 2021