Master Linkage Key (MLK)

The Master Linkage Key is a system of continuously updated links within and between core health-related datasets in NSW and the ACT. Both person and family-based extractions are available, as are tailored linkage services using additional datasets.

Quality assurance checks are regularly carried out on the Master Linkage Key.  For more information on our quality checks and procedures see the Quality Assurance page. 

CHeReL Master Linkage Key

  • 188 Million records
  • 15 Million people
  • 14 average links per person

NSW NSW data that contributes to the CHeReL Master Linkage Key

Admitted Patient Data Collection

Jul 2001 - Mar 2020
49,437,040 records

(updated quarterly)

Private hospitals until June 2019

 

Emergency Department Data Collection

Jan 2005 - Mar 2020
36,851,994 records

(updated quarterly)

 

 

 

Perinatal Data Collection

Jan 1994 - Dec 2019
2,396,727 records

45 and Up Study

Updated Jan 2018
266,750 records

Central Cancer Registry

Jan 1972 - Dec 2016
1,277,181 records

RBDM death registrations

Jan 1985 - Mar 2020
1,641,530 records

(updated quarterly)

RBDM birth registrations

Jan 1994 - Dec 2019
2,442,767 records

Notifiable Conditions Information Management System

Jan 1993 - Dec 2019
1,490,009 records

Perinatal Death Review Database

Jan 2000 - Dec 2016
12,626 records

Cause of Death Unit Record File

Jan 1985 - Dec 2018
1,577,461 records

NSW ANZDATA

1963 - 2016
223,374 records

Mental Health Ambulatory Data Collection

Jan 2001 - Dec 2019
46,710,576 records

NSW Pap Test Registry

Jul 1996 - Jun 2017
15,075,884 records

Australian Early Development Census

2009,2012,2015,2018
391,732 records

NSW Ambulance

Jan 2005 - Mar 2020
10,960,551 records

BreastScreen NSW

Jan 1998 - Dec 2016
6,122,103 records

ACT ACT data that contributes to the CHeReL Master Linkage Key

Admitted Patient Collection

Jul 2004 - Jun 2018
1,336,402 records

Emergency Department Data Collection

Jul 2005 - Jun 2018
1,535,463 records

Cancer Registry

Jan 1994 - Dec 2017
36,399 records

ACT Perinatal Data Collection

Jan 1997 - Dec 2017
79,286 records

Notifiable Diseases Management System

Jan 2000 - June 2019
72,161 records

ACT BDM death registrations

Jan 1997 - Dec 2018
40,454 records

ACT BDM birth registrations

Jan 1997 - June 2020
132,232 records

Australian Early Development Census

2009,2012,2015,2018
20,510 records

ACT Kindergarten Health Check

Jul 2014 - Jul 2016
15,124 records

ACT ANZDATA

1963 - 2016
15,942 records

ACT Ambulance

2011 - 2018
277,236 records

Upcoming Upcoming data that contributes to the CHeReL Master Linkage Key

External Datasets

For information on other frequently-linked datasets outside the MLK, see the additional datasets page.