Measuring the gap: accuracy of the Western Australian hospital morbidity data in the identification of adult urban Aboriginal and Torres Strait Islander people.

OBJECTIVE

To assess the sensitivity of the recording of Aboriginality in the Western Australia Linked Data.

METHODS

This was a follow-up study using record linkage. Demographic data was obtained from 993 adult, urban-dwelling Aboriginal Australian participants in the Perth Aboriginal Atherosclerosis Risk study (PAARS). These were linked to the Western Australian Linked Data (State-wide hospital admissions and discharges, and deaths) to provide the number of admissions and Indigenous status coding from 1980 to 2006.

RESULTS

There were 14,413 admissions for PAARS participants in the study period. The sensitivity of coding of Indigenous status in hospital admissions data significantly improved over time, exceeding 0.9 in every year since 2002. Prior to 2002 sensitivity was around 0.8, but poorer for males, with some anomalous years.

CONCLUSIONS

The coding of Indigenous status in the Western Australia Hospital Morbidity Database since 2002 has improved. The data from earlier decades must be approached with more caution.

IMPLICATIONS

The improved accuracy of identification of Indigenous status in the Western Australia Hospital Morbidity Database allows comparative studies of adult Aboriginal and non-Aboriginal population health outcomes to be undertaken with confidence.