Id: team identifier, A: academic, C: commercial.
For stage 3, three additional variables were identified for matching in addition to SLK-581: postcode of residence, aged care assessment date and assessment team identifier.
Note: See note to Table 3 for definition of keys; '600' series include assessment date; '700' series linkage keys include assessment team identifier.
The least specific keys investigated for use when aged care assessment date, assessment team identifier or date of death (in conjunction with region) were available were keys 64, 46 and 74, respectively, in Table 3.
Match keys to be used for linking were defined in terms of the SLK-581 (divided into five components) and additional available linkage data - postcode, aged care assessment date and assessment team identifier for stage 3.
This equates to key 20 if client region is the only additional match data, key 64 if aged care assessment date and region are included and key 46 if assessment team identifier and region are included.
(c) 'Worst case' FMR is estimated assuming that the number of categories within a key element is equal to that implied by the most common category (s3: 72, g2: 11, dmob: 182, yob: 19, s: 2, st: 3, pc2: 11, pc: 156, aged care assessment date: 161, assessment team identifier: 25).
For comparative purposes, an estimated 'worst case' false match rate is also presented in Table 4. Overall, 76289 matches were identified in stage 3: 60780 using keys incorporating assessment date, a further 7255 using keys with assessment team identifier, and 8254 using keys which did not include assessment data (Table 5).
Decoding can only be done by the investigator or another member of the research team; d) identified: biological materials to which identifiers, such as name, patient number, or clear pedigree location, are attached and made available to the researchers [ 17].
Data were effectively anonymised ('pseudonymised') before they were transferred to the evaluation team, with patient identifiers removed and a unique patient identifier (the 'NHS number') encrypted.
