Evidence for the use of an algorithm in resolving inconsistent and missing Indigenous status in administrative data collections

Abstract

Measures of the gap in living standards, life expectancy, education, health and employment between Indigenous and non-Indigenous Australians are primarily derived from administrative data sources. However, Indigenous identification in these data sources is affected by administrative practices, missing data, inconsistency, and error. As these factors have changed over time, assessing whether the gap between Indigenous and non-Indigenous Australians has changed over time, based on data unadjusted for these sources of error can potentially lead to misguided conclusions. Combining administrative data on the same individuals collected from different sources provides a method by which a more consistent derived Indigenous status can be applied across all records for an individual within a linked data environment. We used the Western Australian Data Linkage system to produce derived Indigenous statuses for individuals using a range of algorithms. We found that these algorithms reduced the amount of missing data and improved within-individual consistency. Based on these findings, we recommend our Multi-Stage Median algorithm be used as the standard indicator of Indigenous status for any reporting based on administrative datasets when multiple datasets are available for linkage, and that algorithmic approaches also be considered for improving the quality of other demographic variables from administrative data sources.

Record linkage study of the pathogen‐specific burden of respiratory viruses in children

“…Incidence rates were calculated using person‐time‐at‐risk as the denominator, derived from dates of birth, death and end of the study (31 December 2012). Aboriginal children were identified using a derived variable provided by the WA Data Linkage Branch …”

Changing mortality patterns in Kimberley Aborigines

“…This back casting process adjusts for changes in classification over time . The Aboriginal births and deaths obtained from Births and Mortality Registration were used in estimating the Aboriginal population; identification of Aboriginal births and deaths used the Western Australia (WA) Data Linkage system to determine the validity of Aboriginality. For example, if a deceased person did not have Aboriginality included on the death record, the data linkage system would check birth, hospital, marriage and other data sets to determine whether or not that person was Aboriginal.…”

Probabilistic linkage of national immunisation and state-based health records for a cohort of 1.9 million births to evaluate Australia’s childhood immunisation program

“…for sex), when we used the birth registration values. Indigenous status was derived using three algorithms proposed by Christensen et al [17] (for always Indigenous, ever Indigenous, and using a multi-stage median algorithm [our base case]), which provides an application of the theory outlined in 'National Best Practice Guidelines for Data Linkage Activities Relating to Aboriginal and Torres Strait Islander People' [18]. …”