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

  • 147 Million records
  • 12.6 Million people
  • 11.7 average links per person

NSW NSW data that contributes to the CHeReL Master Linkage Key

Admitted Patient Data Collection

Jul 2001 – Jun 2017
40,862,014 records

(updated quarterly)

Private hospitals until Jun 2016

 

Emergency Department Data Collection

Jan 2005 – Jun 2017
28,306,393 records

(updated quarterly)

 

 

 

Perinatal Data Collection

Jan 1994 – Dec 2015
2,011,490 records

45 and Up Study

Updated Sep 2017
266,906 records

Central Cancer Registry

Jan 1972 - Dec 2013
1,120,852 records

RBDM death registrations

Jan 1985 - Jun 2017
1,484,790 records

(updated quarterly)

RBDM birth registrations

Jan 1994 - Dec 2015
2,048,962 records

Notifiable Conditions Information Management System

Jan 1993 - Dec 2016
953,044 records

Perinatal Death Review Database

Jan 2000 - Dec 2014
11,103 records

Cause of Death Unit Record File

Jan 1985 - Dec 2015
1,418,797 records

Mental Health Ambulatory Data Collection

Jan 2001 - Jun 2017
38,447,142 records

NSW Pap Test Registry

Jul 1996 - Dec 2013
12,525,805 records

Australian Early Development Census

2009, 2012, 2015
311,458 records

NSW Ambulance

Jan 2005 - Dec 2016
8,297,897 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
1,098,879 records

Emergency Department Data Collection

Jul 2005 - Jun 2016
1,243,417 records

Cancer Registry

Jan 1994 - Dec 2014
29,284 records

ACT Perinatal Data Collection

Jan 1997 - Dec 2012
52,996 records

Notifiable Diseases Management System

Jan 2000 - Dec 2015
49,501 records

ACT BDM death registrations

Jan 1997- Jun 2016
34,402 records

ACT BDM birth registrations

1997-2012
84,282 records

Australian Early Development Census

2009, 2012, 2015
14783 records

ACT Cervical Screening Registry

Jan 1994 - Dec 2015
821,528 records

Upcoming Upcoming data that contributes to the CHeReL Master Linkage Key

NSW PTR

Jan 2016- Dec 2016

External Datasets

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