Major impediments to producing a complete picture of Indigenous mortality in Australia are the incomplete identification of Indigenous status in death records and the experimental nature of the recently adopted population estimates . As a result of the incomplete identification of Indigenous status in death records, the 2,558 deaths registered in 2011 where the deceased person was identified as Indigenous is certainly an underestimate of the actual number of Indigenous deaths.
The extent to which the number of Indigenous deaths is under-estimated is not available for recent years , but the ABS does make adjustments to the number of registered deaths in preparing their estimates of life expectancy. It is likely that these adjustments are in line the ABS’s assessment of the completeness of recording of Indigenous deaths in 2006-2007, which was based on a comparison of deaths in those years with Indigenous status reported in the 2006 Census . Based on this comparison, the ABS estimated that the Australia-wide level of Indigenous identification in deaths notifications in 2006-2007 was 92%, a level much higher than previous estimates (around 56%) .
The estimated completeness of identification of Indigenous people in death registrations has improved since the 1990s, mostly because of improvements in NSW and Qld, but there is still some doubt about the actual levels of identification . As a result, the ABS notes that caution should be exercised in the interpretation of the estimates of Indigenous mortality, particularly estimates of trends over time . This caution is reflected in recent ABS publications that do not include detailed tables of Indigenous deaths, nor information about overall death rates. As a result, there is no consistency about the extent of information available for recent years. Reflecting this, readers should be aware that the following sections vary in terms of the years to which they relate.
Comparison of Indigenous and non-Indigenous mortality needs to take account of differences in the age structures of the Indigenous and non-Indigenous populations using a process known as standardisation.
Age-standardised death rates can be calculated when detailed information about Indigenous deaths, including sex and age, is available . By direct age-standardisation, Indigenous rates can be more accurately compared with non-Indigenous rates. This method also allows for time-series comparisons.
When detailed information is not available, it is still possible to use indirect standardisation to estimate standardised mortality ratios (SMRs), as has been done in previous versions of this Overview. SMRs allow for the comparison of numbers of registered Indigenous deaths with the numbers expected from the corresponding age-sex-specific death rates for the total populations. An SMR is the ratio of the numbers registered and expected.
After age-adjustment, the death rate for Indigenous people living in NSW, Qld, WA, SA and the NT – the jurisdictions with adequate levels of Indigenous identification – was 1.9 times the rate for non-Indigenous people in 2006-2010 (Table 5) . The rates for Indigenous people were highest in the NT (1,541 per 100,000) and WA (1,431 per 100,000).
|Jurisdiction||Indigenous rate||Non-Indigenous rate||Rate ratio|
|Source: Australian Health Ministers’ Advisory Council, 2012 |
|NSW, Qld, WA, SA and the NT||1,151||597||1.9|
Between 1991 and 2010, there was a 33% reduction in the death rates for Indigenous people in WA, SA and the NT; there was also a significant closing of the gap in death rates between Indigenous and non-Indigenous people during this time period .
In 2009, the ABS revised its estimates for expectation of life at birth for Indigenous people . After adjustment for the underestimate of the number of deaths identified as Indigenous, the ABS estimated that Indigenous males born in 2005-2007 could expect to live to 67.2 years, 11.5 years less than the 78.7 years expected for non-Indigenous males (Table 6). The expectation of life at birth of 72.9 years for Indigenous females in 2005-2007 was almost 10 years less than the expectation of 82.6 years for non-Indigenous females.
These revised estimates are significantly higher than previous estimates. Importantly, comparisons between the original and revised estimates should not be interpreted as a change in Indigenous life expectancy, but should be seen as the result of a revision in statistical methods used to calculate life expectancy .
|Source: ABS, 2009 |
For those jurisdictions with reasonable information about Indigenous deaths, the median age at death4 in 2011 for Indigenous males ranged from 50.3 years for those living in SA to 58.5 years for those living in NSW . These levels were around 20 years less than those for non-Indigenous males, which ranged from 66.6 years (NT) to 79.7 years (SA). The median age at death for Indigenous females in 2011 ranged from 50.3 years for those living in SA to 66.2 years for those living in NSW. These levels were also around 20 years less than those for non-Indigenous females, which ranged between 73.5 years (NT) and 85.3 years (SA).
In 2007-2011, age-specific death rates were higher for Indigenous people than for non-Indigenous people across all age-groups, but the rate ratios were highest in the young and middle adult years (Table 7) . (The rate ratios, based on the numbers of deaths registered, vary according to the levels of Indigenous identification (see above).)
|Age-group (years)||Indigenous||Non-Indigenous||Rate ratio|
|Source: ABS, 2012 |
The infant mortality rate (IMR) is the number of deaths of children under one year of age in a calendar year per 1,000 live births in the same calendar year. For those jurisdictions with reasonable information about Indigenous deaths in 2009-2011, the highest Indigenous IMRs occurred in the NT; the lowest rate for Indigenous males was in SA (4.3) and for females was in WA (3.7) (Table 8) .
|Source: Derived from ABS, 2012 |
In the five-year period from 2006 to 2010, Indigenous infants most commonly died from International Classification of Disease (ICD) ‘Conditions originating in the perinatal period’, including birth trauma, disorders relating to foetal growth, and complications from pregnancy, labour and delivery . Indigenous infants died from ICD ‘Conditions originating in the perinatal period’ at twice the rate of non-Indigenous infants. The second most common cause of infant death was ICD ‘Congenital malformations’, for which Indigenous and non-Indigenous infants had similar rates (rate ratio of 1.2). The third most common cause of infant death was for ICD ‘Signs, symptoms and ill-defined conditions’, which includes sudden infant death syndrome (SIDS); Indigenous infants died at three times the rate of non-Indigenous infants (and, for SIDS alone, twice the rate).
From 1991 to 2010, there have been significant declines in IMRs for Indigenous and non-Indigenous infants in WA, SA and the NT: the rate has declined by 62% for Indigenous infants and by 43% for non-Indigenous infants . The gap between Indigenous and non-Indigenous infants has closed substantially.
For deaths identified as Indigenous in 2006-2010, circulatory diseases (also known as cardiovascular disease, which includes heart disease and stroke) was the most common cause of death for Indigenous people living in NSW, Qld, WA, SA and the NT, accounting for 26% of Indigenous deaths . The next most common causes of death were neoplasms (almost entirely cancer) (19% of Indigenous deaths) and external causes of death (injury) (15% of Indigenous deaths). For all major causes of death, Indigenous people died at higher rates than did non-Indigenous people (Table 9).
|Cause of death||Rate||Rate ratio|
|Source: Australian Health Ministers’ Advisory Council, 2012 |
|Endocrine, metabolic and nutritional disorders (including diabetes)||118||22||5.4|
|Nervous system diseases||27||24||1.1|
|Infectious and parasitic diseases||25||8.7||2.9|
|Conditions originating in the perinatal period||6.0||2.8||2.2|
In 2010, the leading specific causes of death differed for Indigenous males and females living in NSW, Qld, WA, SA and the NT . For Indigenous male and females, the two leading specific causes of death were coronary heart disease (also known as ischaemic heart disease) followed by diabetes; the third leading cause of death were intentional self-harm (suicide) for Indigenous males and cerebrovascular diseases for Indigenous females. For non-Indigenous males, the leading causes of death were coronary heart disease, lung and related cancers, and cerebrovascular disease. For non-Indigenous females, the leading causes of death were coronary heart disease, cerebrovascular disease, and dementia and Alzheimer’s disease.
In Australia in 2003-2005 (the most recent period for which detailed data are available), six (10%) of the 60 maternal deaths where Indigenous status was known were of Indigenous women (Indigenous status was not reported in 8% of the deaths) .
Reflecting the higher rate of confinements among Indigenous women, the maternal mortality ratio for Indigenous women in 2003-2005 was 21.5 deaths per 100,000 confinements, almost three times higher than the ratio of 7.9 per 100,000 for non-Indigenous women (Table 10) (Derived from ). For direct maternal deaths, the ratio of 7.2 per 100,000 for Indigenous women was twice the ratio of 3.6 per 100,000 for non-Indigenous women.
|Indigenous status||Confinements||Maternal deaths||Maternal mortality ratio|
|Source: Derived from Sullivan, Hall, King, 2008 |
|Direct and indirect maternal deaths||6||21.5|
|Direct maternal deaths||2||7.2|
|Direct and indirect maternal deaths||59||7.9|
|Direct maternal deaths||27||3.6|
Avoidable mortality refers to deaths that could have been prevented with timely and effective health care, including early detection and effective treatment, as well as appropriate modifications of lifestyle behaviours (such as quitting smoking) .
In the five-year period from 2006 to 2010, there were 6,777 deaths from avoidable causes, representing almost three-quarters (74%) of the deaths among Indigenous people aged 0-74 years living in NSW, Qld, WA, SA and the NT (compared with 66% of non-Indigenous deaths) .
The age-standardised rates of avoidable deaths for Indigenous people were highest in the NT (787 per 100,000) and lowest in NSW (382 per 100,000) in 2006-2010 . Indigenous people died from avoidable causes at 3.5 times the rate of non-Indigenous people living in NSW, Qld, WA, SA and the NT.
In 2006-2010, the most common conditions contributing to avoidable deaths among Indigenous people living in NSW, Qld, WA, SA and the NT were coronary heart disease (19%), cancer (17%), diabetes (10%), and suicide (8.5%) . The death rates from avoidable causes were around twice as high for Indigenous people than for non-Indigenous people for cancer and suicide, four times as high for coronary heart disease, and 13.5 times as high for diabetes.
Between 1991 and 2010, there was a 24% decline in the death rate from avoidable causes for Indigenous people living in WA, SA and the NT . The difference in rates between Indigenous and non-Indigenous people has decreased.
4. The median age at death is the age below which 50% of people die. Because the measure partly reflects the age structures of the respective populations, it is a less precise measure than age-specific death rates, which are summarised below.