The Data LinkageThe process of establishing whether two or more pieces of information belong to or describe the same person, family, event, place or time period. Branch (DLB) links many data collections from the Department of Health WA (DOHWADepartment of Health Western Australia) and other agencies. The DLB maintains a set of ‘core’ linkages which are updated on a regular basis. The following diagram shows the core datasets and some other infrastructure ‘satellite’ linkages.

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The Department of Health collects and maintains the following core statewide data collections:

Hospital Morbidity Data Collection

  • Since 1970
  • Linked on a monthly basis
  • Includes all hospitals in WA (public and private)
  • Comprised of around 20,000,000 electronic inpatient records back to 1970, snapshots of waitlist data dating back to 1991 and hospital survey data since 1993 (the Beds and Services Survey).

Emergency Department Data Collection

  • Since 2002
  • Linked on a weekly basis
  • Contains data on emergency department activity in WA’s public hospitals as well as ED activity in private hospitals under contract with the WA Government.
  • Include 4 systems:
    • Emergency Department Information System (EDIS) - used by all EDs in metropolitan public hospitals and the Joondalup Health Campus
    • Health Care and Related Information System (HCARe) - used by all rural public hospital (except Bunbury Regional Hospital)
    • The Open Patient Administration System (TOPAS) - used by Bunbury Regional Hospital
    • lThe Electronic Patient Administration System (ePAS) - used by Peel Health Campus

Mental Health Information System

  • Since July 1966
  • Linked on a monthly basis
  • Patient based system (every patient is allocated a unique number)
  • Psychiatric episodes can be inpatient (public and private) and outpatient (public only)
  • Inpatient data is sourced from:
    • Community Accommodation Support Program Hostels
    • Community Residential Facilities; and
    • Acute general hospitals
  • Outpatient data is sourced from:
    • Designated Psychiatric Inpatient Units
    • Psychiatric Clinics
    • Triage Services
    • Community mental health centres
    • Psychiatric Day centres
    • Outreach programs; and
    • Rehabilitation programs

 Western Australian Cancer Registry

  • Since 1982
  • Linked on a monthly basis
  • Includes all cases of cancer and some other neoplasm types
  • Includes details of non-WA deaths where known
  • Information supplied usually includes demographic data and one or sets of tumour details
  • Case-based, not “event-based” structure

Midwives Notification System

  • Since 1980
  • Linked on a monthly basis
  • 30,000 births per year (including stillbirths)
  • Includes births greater than 20 week’s gestation or more than 400 grams in weight  
  • Information comes the Notification of Case Attended Forms(NOCA)
  • Feeder Systems include
    • STORK (HIN System)
    • Ramsay System
    • South West System
    • SJOG System
    • Midwives Data Entry Package(HDWA)
Also included in the core data sets are:

 Death Registrations

  • Since 1969
  • Linked on a monthly basis
  • All deaths registered in WA
  • Coded cause of death data is updated annually and can be 2 years after the event

Birth Registrations

  • Since 1974
  • Linked on a monthly basis
  • All children born in WA
  • Contains information about the child, mother and father

Marriage Registrations

  • Since 1984
  • Linked on a monthly basis
  • Not released for research projects, just used for individual and family connections linkages 

WA Electoral Commission Records

  • Since 1988
  • Linked on a quarterly basis
  • Used primarily for linkage purposes and selection of controls