The Queensland Department of Health's Data Linkage Service facilitates the integration of health and non-health data for enhanced research and analysis, funded by multiple sources since 2005. It employs a master linkage file to connect patient data across various health facilities while ensuring privacy and compliance with legal protocols for data requests. The linkage process uses probabilistic and deterministic methods to match records, with all requests requiring approval from data custodians and ethics committees.

1. Queensland Department of
Health Data Linkage Service
Catherine Taylor and Trisha Johnston,
Statistical Analysis and Linkage Unit,
Statistical Services Branch

2. Health data linkage in Australia
• Funded by National Collaborative Research
Infrastructure (NCRIS) Strategy and
coordinated nationally by the Population
Health Research Network (PHRN) since 2005
• NCRIS and one-off DEEDI Funds received in
Queensland since 2011
• Queensland Department of Health now
recurrently funds 10 linkage positions and
various in-kind in addition to NCRIS funds

3. QH Data Linkage Team
• Production Linkage – creation of a Master
Linkage File (MLF) with enduring linkages
between core health data collections (TBD)
which is maintained in near-real time
• Request linkage – provision of data from the
MLF and custom linkage for ad hoc research
and government requests

5. Access to linked data
• Requests for linked data must be made in accordance
with Queensland Health’s data release protocols.
• Privacy and confidentiality of all administrative data
are covered by legislation.
• Linkage of data for requests occurs in a secure
environment and no patient identifying details are
released to those requesting linkage services.
• All requests must be approved by the data custodian
for each data collection being linked and research
requests must have ethics approval in addition to data
custodian and Director-General approval.

6. Access to linked data
For research, data are available via Public Health Act
application and approval from an authorised ethics
committee
1. See QH data linkage website and Framework at
– https://www.health.qld.gov.au/hsu/link/datali
nk.asp
– http://www.health.qld.gov.au/hsu/pdf/other/q
lddatalinkframework.pdf
2. Contact HSBresearch@health.qld.gov.au

7. Why link?
• Combining data sources can provide far richer
information – whole > sum of parts
• Track patients across facilities
• Obtain follow-up information on a cohort of
interest
• Ensure study participants have not died when
making contact

8. What can we link?
• Anything! Subject to approval
• Must have compatible identifying information
– Name
– DOB
– Address
– Common ID
• Doesn’t have to involve SSB-owned data – we can
still provide stand-alone linkage service
• Discuss feasibility with QH linkage team

9. What we have linked – examples 1
• Health-related:
– ED
– ambulance
– deaths
– mental health
– pathology
– notifiable conditions
– vaccinations
– Master Linkage File

10. What we have linked – examples 2
• Non health-related:
– Main Roads traffic accidents
– Police and Court Service
– Education
• Other:
– Various cohort groups defined by client eg.
Patients undergoing certain procedures

11. Master linkage file

12. How do we link?
• Most linkage work in QLD Health uses
probabilistic methodology
• Occasionally we use a deterministic method
such as Statistical Linkage Key (SLK)
• Software:
– Production – Choicemaker
– Requests – Linkage Wiz

13. Probabilistic linkage
• Uses probability to calculate likelihood of two
separate records belonging to the same
person
• Where probability is lower, eg. Common
names, inaccurate data, we get ‘grey area’
• Good quality data results in clearer definition
between true and false links

14. Typical distribution of linked pairs
True non-links True links
Uncertain links

15. Linkage Wiz setup 1

16. Linkage Wiz setup 2

17. Data linkage website

18. Queensland Data Linkage
Framework

19. Contacts & Links
General linkage queries:
catherine.taylor2@health.qld.gov.au
Tel: 07 3234 0709
Data linkage website:
https://www.health.qld.gov.au/hsu/link/datalink
.asp