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 2,620 deaths registered in 2012 where the deceased person was identified as Indigenous is certainly an underestimate of the actual number of Indigenous deaths.
Based on a linkage study of Indigenous identification in deaths registration and the 2011 Census undertaken by the ABS in revising its estimates of the expectation of life of Indigenous people (see ‘Life expectancy’), it is likely that the overall identification of Indigenous people in death registrations was around 87% .
The levels of under-identification, which differed by age-group, jurisdiction and remoteness of residence, were taken account of in the new estimates of Indigenous life expectancy. The ABS noted that correction of the under-estimates of death numbers and rates would need similar adjustments. These findings confirm the caution that the ABS notes 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. (The process is also referred to as age-adjustment.)
Direct standardisation, the preferred method, applies detailed information about Indigenous deaths, including sex and age, to a ‘standard’ population . (In Australia, the 2001 Australian estimated resident population (ERP) is generally used as the standard population.) Direct standardisation enables accurate comparisons of Indigenous and non-Indigenous rates, and time-series analyses.
If detailed information is not available, it is still possible to use indirect standardisation to estimate standardised mortality ratios (SMRs). 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 population or, preferably, the non-Indigenous population. The SMR is the ratio of the numbers of deaths (or of other health measures) registered/observed to the number expected.
There were 2,620 deaths in Australia in 2012 where the deceased person was identified as Indigenous . For NSW, Qld, WA, SA and the NT, the only jurisdictions with adequate identification of Indigenous status, the age-standardised death rate of 1,128 per 100,000 population for Indigenous people was 2.0 times the rate for their non-Indigenous counterparts.
More detailed information about death rates is available for the five-year period 2006-2010 for people living in NSW, Vic, Qld, WA, SA and the NT . After age-adjustment, the death rate for Indigenous people living in those jurisdictions was 1.9 times the rate for non-Indigenous people (Table 1) . 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: AIHW, 2013 |
|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 2013, the ABS published revised 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 Australia in 2010-2012 could expect to live to 69.1 years, 10.6 years less than the 79.7 years expected for non-Indigenous males. The expectation of life at birth of 73.7 years for Indigenous females born in Australia in 2010-2012 was 9.5 years less than the expectation of 83.1 years for non-Indigenous females.
Revised estimates were also published for Indigenous people living in NSW, Qld, WA and the NT (Table 2) . (It should be noted that the table includes two estimates for Australia. The ‘headline’ estimate includes adjustments based on Australia-wide census-related information. The headline estimates should be used in all situations except those requiring comparisons with the estimates for the states and territories, for which Australia-wide census-related information could not be applied. The unadjusted Australian estimate should be used in situations requiring such a comparison.)
|Source: ABS, 2013 |
The median age at death1 in 2012 for Indigenous males ranged from 49.9 years for those living in the NT to 60.6 years for those living in NSW (Table 7) . These levels were around 20 years less than those for non-Indigenous males, which ranged from 67.1 years (NT) to 80.2 years (SA).
The median age at death for Indigenous females in 2012 ranged from 52.8 years for those living in the NT to 63.9 years for those living in NSW and Qld (Table 3) . These levels were also around 20 years less than those for non-Indigenous females, which ranged between 74.0 years (NT) and 85.6 years (SA).
|Source: ABS, 2013 |
In 2008-2012, 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 4) . (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, 2013 |
The infant mortality rate (IMR) is the number of deaths of children aged less than one year in a calendar year per 1,000 live births in the same calendar year. In NSW, Qld, WA, SA and the NT in 2010-2012, the Indigenous IMR (6.4 per 1,000) was around twice as high as the non-Indigenous IMR . The highest Indigenous IMRs occurred in the NT (15.6 for male infants and 11.7 for female infants); the lowest occurred in NSW (3.8 for both male and female infants) (Table 5).
|Source: ABS, 2013 |
In the five-year period 2006-2010, Indigenous infants most commonly died from the International Classification of Diseases (ICD): ‘Certain 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 ‘Certain 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.
Cardiovascular disease was the leading cause of death of Indigenous people in 2012, being responsible for 25% of the deaths of Indigenous people living in NSW, Qld, WA, SA and the NT . The next most common causes of death were neoplasms (mainly cancers) being responsible for 21% of deaths, followed by ICD ‘External causes’ (injury) (15%), ICD ‘Endocrine, nutritional and metabolic diseases’ (including diabetes) (9%) and ICD ‘Diseases of the respiratory system’ (8%). The information needed to make a valid comparison of the relative impacts of these causes among Indigenous and non-Indigenous people in 2012 is not available, so the following comparisons are restricted to some specific causes within each group.2
In terms of specific conditions, coronary heart disease was the leading cause of death of Indigenous people living in NSW, Qld, WA, SA and the NT in 2012 at a rate 2.1 times that of their non-Indigenous counterparts (Table 6) . The other leading specific causes of death of Indigenous people were diabetes (rate ratio: 7.0), lung cancer (2.3) and chronic lower respiratory disease (2.9).
|Cause of death||Number||Rate||Rate ratio|
|Source: ABS, 2014 |
|Coronary heart disease||338||165||2.1|
|Chronic lower respiratory disease||123||74||2.9|
|Land transport accidents||88||20||3.4|
|Symptoms signs and ill-defined conditions||79||22||3.4|
|Cirrhosis and other liver diseases||72||23||4.1|
|Diseases of the urinary system||63||34||2.5|
More detailed information about Indigenous mortality is available for the five-year period 2006-2010 for people living in NSW, Vic, Qld, WA, SA and the NT . During that time period, cardiovascular disease was the most common cause of death for Indigenous people living in those jurisdictions, followed by ICD ‘Neoplasms’ (almost entirely cancer) (19% of Indigenous deaths) and ICD ‘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 7).
|Cause of death||Rate||Rate ratio|
|Source: AIHW, 2013 |
|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 2011, the leading specific causes of death differed for Indigenous males and females living in NSW, Qld, WA, SA and the NT . For Indigenous males 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 was suicide for Indigenous males and chronic lower respiratory 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 (including 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 8) (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 2012, almost 1,500 of the deaths of Indigenous people living in NSW, Qld, WA, SA and the NT were avoidable . After age-adjustment, the rate of avoidable deaths was 3.7 times higher for Indigenous people than for their non-Indigenous counterparts.
More details about avoidable deaths are not available for 2012, but there were 6,777 deaths from avoidable causes among Indigenous people living in NSW, Qld, WA, SA and the NT in the five-year period 2006-2010 . Age-adjusted rates for avoidable deaths of Indigenous people were highest in the NT (787 per 100,000) and lowest in NSW (382 per 100,000). 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 two times higher for Indigenous people than for non-Indigenous people for cancer and suicide, four times higher for coronary heart disease, and 13.5 times higher for diabetes.
Between 1997 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.