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

  • 161 Million records
  • 13.1 Million people
  • 9 average links per person

NSW NSW data that contributes to the CHeReL Master Linkage Key

Admitted Patient Data Collection

Jul 2001 – March 2018
43,312,088 records

(updated quarterly)

Private hospitals until Jun 2017

 

Emergency Department Data Collection

Jan 2005 – March 2018
30,997,952 records

(updated quarterly)

 

 

 

Perinatal Data Collection

Jan 1994 – Dec 2016
2,110,217 records

45 and Up Study

Updated Sep 2017
266,887 records

Central Cancer Registry

Jan 1972 - Dec 2014
1,171,058 records

RBDM death registrations

Jan 1985 - March 2018
1,533,643 records

(updated quarterly)

RBDM birth registrations

Jan 1994 - Dec 2016
2,143,865 records

Notifiable Conditions Information Management System

Jan 1993 - Dec 2016
1,126,477 records

Perinatal Death Review Database

Jan 2000 - Dec 2015
11,876 records

Cause of Death Unit Record File

Jan 1985 - Dec 2015
1,418,797 records

Mental Health Ambulatory Data Collection

Jan 2001 - Jun 2017
39,921,254 records

NSW Pap Test Registry

Jul 1996 - Jun 2017
15,075,884 records

Australian Early Development Census

2009, 2012, 2015
311,788 records

NSW Ambulance

Jan 2005 - Dec 2017
8,580,057 records

BreastScreen NSW

Jan 1988 - Dec 2016
6,122,103 records

ACT ACT data that contributes to the CHeReL Master Linkage Key

Admitted Patient Collection

Jul 2004 - Jun 2016
1,098,880 records

Emergency Department Data Collection

Jul 2005 - Jun 2016
1,243,417 records

Cancer Registry

Jan 1994 - Dec 2015
31,478 records

ACT Perinatal Data Collection

Jan 1997 - Dec 2015
68,534 records

Notifiable Diseases Management System

Jan 2000 - Dec 2015
49,501 records

ACT BDM death registrations

Jan 1997- Jun 2017
36,801 records

ACT BDM birth registrations

Jan 1997-Jun 2017
112,849 records

Australian Early Development Census

2009, 2012, 2015
14783 records

ACT Cervical Screening Registry

Jan 1994 - Dec 2015
821,528 records

ACT Kindergarten Health Check

Jul 2014 - Jul 2016
15,124 records

Upcoming Upcoming data that contributes to the CHeReL Master Linkage Key

NSW RBDM births

up to Dec 2017

NSW Ambulance

up to March 2018

External Datasets

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