Almost all deaths in Australia are registered. However, Indigenous status is not always recorded, or recorded correctly. The incompleteness of Indigenous identification means that the number of deaths registered as Indigenous is an underestimate of the actual number of deaths which occur in the Aboriginal and Torres Strait Islander population.
The extent to which the identification of Indigenous Australians occurs in data collections is referred to as 'coverage' or 'completeness of coverage'. While there is incomplete coverage of Indigenous deaths in all state and territory registration systems, some jurisdictions have been assessed by the Australian Bureau of Statistics (ABS) as having a sufficient level of coverage to enable statistics on Aboriginal and Torres Strait Islander mortality to be produced. These jurisdictions are Queensland, South Australia, Western Australia and the Northern Territory, and their data have been combined for 1999-2003 for an analysis of Indigenous mortality. Longer term mortality trends discussed in this Chapter are based on an analysis of data from three jurisdictions - South Australia, Western Australia and the Northern Territory - being the only jurisdictions with 12 years of reasonable coverage of Indigenous deaths registrations.
Deaths can be analysed by year of occurrence of death or by year of registration of death. While the majority of deaths are registered in the year they occur, some of those registered in a given year occurred in previous years. Delays in registration can occur when deaths are subject to the findings of a coroner or when deaths occur in remote areas. Late deaths registrations are more common for Indigenous people than non-Indigenous people, and therefore have a greater impact on mortality statistics.
For example, 95% of deaths of non-Indigenous Australians that occurred in 2002 were registered in that year while 5% were registered in 2003. For Indigenous deaths, the corresponding figures were 86% in 2002 and 14% in 2003. The analyses of deaths reported in this chapter are based on year of occurrence of death for the period 1999-2002 - the latest year for which year of occurrence data are available - augmented by year of registration of death for 2003 - the latest year for which such data are available.
Causes of death statistics provided in this chapter are based on the tenth revision of the International Classification of Diseases (ICD-10). Mortality coding using ICD-10 was introduced in Australia for deaths registered from 1 January 1997. All rates and ratios derived in this Chapter are calculated using the 'low series' ABS experimental population projections of the Indigenous population based on the 2001 Census.