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
-
310 Million
records
-
18 Million
people
-
17
average links per person
NSW NSW data that contributes to the CHeReL Master Linkage Key
Jul 2001 - Dec 2021
55,865,973 records
(updated quarterly)
Private hospitals until June 2021
Jan 2005 - Dec 2021
41,953,906 records
Jan 1994 - Dec 2020
2,489,268 records
Updated Jan 2018
266,550 records
Jan 1972 - Dec 2019
1,448,212 records
Jan 1985 - Dec 2021
1,737,742 records
Jan 1994 - Dec 2020 (and 1990-1993)*
3,148,862 records
*identifiers for these records may not be complete
Jan 1993 - Dec 2019
1,490,009 records
Jan 2000 - Dec 2020
14,127 records
Jan 2020 - Dec 2021
213,833 records
Jan 2001 - Dec 2021
53,212,631 records
1963 - 2020
328,605 records
Jul 1996 - Jun 2017
15,075,884 records
2009,2012,2015,2018
391,732 records
Jan 2005 - Dec 2021
12,445,010 records
Jan 1998 - Dec 2021
7,735,661 records
1985 - 2019
685,715 records
Jul 2015 - Dec 2021
95,343,552 records
Jan 1985 - Dec 2019
1,633,109 records
ACT ACT data that contributes to the CHeReL Master Linkage Key
Jul 2004 - Jun 2021
1,699,559 records
Jan 1994 - Dec 2019
41,115 records
Jul 2005 - Jun 2021
1,979,523 records
Jan 1997 - Dec 2019
90,225 records
Jan 2000 - June 2021
84,584 records
Jan 1985 - Jun 2021
46,394 records
Jan 1997 - Dec 2020
135,321 records
2009,2012,2015,2018
20,510 records
2014, 2015, 2016
15,124 records
1963 - 2020
17,674 records
2011 - 2020
373,750 records
Upcoming Upcoming data that contributes to the CHeReL Master Linkage Key
