SA Data Linkage Workshop

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SA Data Linkage Workshop
Future directions for the linkage of datain the
South Australian health system Adelaide 27-28
October 2003
Overview of the WA data linkage system
John Bass
Curtin University of Technology
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The early years (1970 - 1994)

• Mike Hobbs returns from Oxford and inspires the
  collection of hospital separation records
  with full identifiers

• Ad hoc use of record linkage in epidemiologic
  cohort studies

• The Maternal and Child Health Research Database

• The Roadwatch Road Injury Database

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Conception and birth of the Data Linkage
Unit(1990 - 1998)

• Increase in ad hoc record linkage activity

• Proliferation of identified data sets amongst
  researchers

• Collaboration between UWA and DoH

• WA Lotteries Commission grant 830,000 over
  three years

• Early development of the Data Linkage Unit (DLU)

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Core data sets 1980 - 1994
2 million chains
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Late childhood 1999 - 2000
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Early adolescence 2000 - 2003
Geocoding 5.1 million electoral, midwives,
hospital and death records 1 million
individuals
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Overview of the WA data linkage system
A growth spurt 2003 - 2004
Total Population
Defined Population Subset
Family Connections Genealogic Database
Linked Health Records
System already exists
Nuclear Families
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Maturity 2005 ?
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Overview of the WA data linkage system
The DLU links storage system
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NO!
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Episodes
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a pause for breath . . . . . . .
any questions ?
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Overview of the WA data linkage system
Connecting the families
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birth
hospital
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birth register
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birth
hospital
midwife mother
midwife baby
midwife
birth register mother
birth register father
birth register baby
birth register
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Overview of the WA data linkage system
Storage the WA Links System

• multiple datasets
• chains of links
• dynamic updates (links/splits)
• history system
• quality assessment

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Linkage error rate over time
Overview of the WA data linkage system
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The DLU linked data supply process

• Receive application from researcher

• Approve application

• Extract episodes

• Create list of individuals

• Extract data

• Encode or aggregate possible identifiers

• Encrypt data file(s)

• Send data file(s) to researcher

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Overview of the WA data linkage system
Challenges in running the WA linkage projectin
ascending order of difficulty

• good software and hardware

• finding (training) staff with good data linkage
  abilities

• finding (training) analysts able to work with
  complex file structures

• data availability and quality

• poor technical ability in agencies supplying
  data

• funding

• intra- inter-agency rivalry / territoriality
  PEOPLE PEOPLE PEOPLE

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Overview of the WA data linkage system
Any comments or questions ?
?