Mortality

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 population estimates [1]. As a result, the 2,279 deaths registered in 2006 where the deceased person was identified as Indigenous is certainly an underestimate of the actual number of Indigenous deaths.

Assessment by the ABS of the completeness of recording of Indigenous deaths is based on a comparison of registered Indigenous deaths with an estimate of the expected number of Indigenous deaths for the particular jurisdiction. The estimated completeness of identification of Indigenous people in death registrations has improved generally in recent years, but was still generally quite poor in 2002-2006 [1] . Australia-wide, only 55% of Indigenous deaths were identified correctly – the Northern Territory (90%) was the only jurisdiction with a reasonable proportion of Indigenous deaths identified correctly. The proportions for the other jurisdictions were: NSW (45%), Victoria (32%), Queensland (51%), WA (72%) and SA (62%). Estimate weren’t available for Tasmania and the ACT. Reflecting the various levels of under-identification of Indigenous status in death registrations, caution needs to be exercised in interpretation of the figures presented in this report. It is possible that the true figures could be up to 30% higher than those presented here.

The poor coverage, coupled with the need to update the procedures for estimating coverage based on population figures derived from the 2001 census, has meant that the recent ABS publications 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.

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Standardised death rates

After adjusting for the differences in the age structures of the Indigenous and non-Indigenous populations and for the incomplete identification of Indigenous status in death registrations, the numbers of deaths of Indigenous people in 2000-2004 were around four times higher than the numbers expected from the age-sex-specific death rates for the total Australian populations (Table 1) [2-6]. (The ABS warns that the projected numbers of deaths should be interpreted with caution [2]. It is possible that the standardised mortality ratios (SMRs) based on the projected numbers of deaths may over-estimate the differences between Indigenous and total population mortality, but it is likely that the true ratios will be closer to these estimates than to those based solely on death registrations.)

Box 1
Comparison of overall death rates needs to adjust for differences in the age structures of the Indigenous and non-Indigenous populations in a process known as standardisation. The lack of detailed information about Indigenous deaths in terms of sex and age means that it is not possible to estimate standardised death rates, but it is possible to compare the numbers of registered and projected Indigenous deaths with the numbers expected from the corresponding age-sex-specific death rates for the total populations. This comparison produces what are called standardised mortality ratios (SMRs). The comparisons reported here are based on the 2002 age-specific death rates for the corresponding total Australian populations.


Table 1 Registered and projected Indigenous deaths and standardised mortality ratios (SMRs), by sex and jurisdiction, Australia, 2000-2004

 
Registered deaths
   
Number
  
SMR
Jurisdiction  
Persons
Males
Females
   Persons Males Females
Australia  
10,550
6,037
4,513
2.3
2.2
2.5
                 
NSW  
2,445
1,412
1,033
1.9
1.8
2.0
Vic  
477
n/a
n/a
1.4
n/a
n/a
Qld  
2,838
1,601
1,237
2.3
2.2
2.5
WA  
1,861
1,068
793
2.7
2.5
2.8
SA  
644
359
285
2.6
1.9
2.8
NT  
2,225
1,285
940
3.9
3.7
4.1
 
Projected deaths
Australia  
18,495
10,584
7,911
4.0
3.9
4.4
   
NSW  
5,371
3,102
2,269
4.1
3.9
4.4
Vic  
1,144
n/a
n/a
4.0
n/a
n/a
Qld  
5,312
2,997
2,315
4.4
4.1
4.7
WA  
2,584
1,483
1,101
3.7
3.5
4.0
SA  
982
547
435
3.9
3.6
4.3
NT
2,365
1,366
999
4.1
3.9
4.4

Source: Derived from ABS 2000-2005 [2-8]

Note: Figures for Australia include the Australian Capital Territory, Tasmania and Other Territories (Christmas Island, Cocos (Keeling) Islands and the Jervis Bay Territory)

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Expectation of life

After adjustment for the underestimate of the number of deaths identified as Indigenous, the ABS estimates that Indigenous males born in 1996-2001 could be expected to live to 59.4 years, more than 17 years less than the 76.6 years expected for all males in 1998-2000 (Table 2) [1]. The expectation of life at birth of 64.8 years for Indigenous females in 1996-2001 was more than 17 years less than the expectation of 82.0 years for all Australian females in 1998-2000.

Table 2 Expectation of life at birth for Indigenous people and the total population, Australia and selected States, 1996-2001

Population Males Females
Indigenous, 1996-2001    
Australia 59.4 64.8
New South Wales / Victoria 60.0 65.1
Queensland 58.9 62.6
Western Australia / South Australia 58.5 67.2
Northern Territory 57.6 65.2
Total population, 1998-2000    
Australia 76.6 82.0

Source: ABS, 2007 [1]

Note: The Australian Indigenous estimates are based on the adjusted numbers of deaths for NSW, Victoria, Queensland, WA, SA and the NT, and do not include deaths for the ACT and Tasmania

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Age at death

For those jurisdictions with reasonable information about Indigenous deaths, the median age at death in 2006 ranged from 45.4 years for Indigenous males living in the NT to 59.3 years for those living in NSW [9]. (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.) These levels are around 20 years less than those for non-Indigenous males, which were generally around 76-78 years. The median age at death for Indigenous females in 2005 ranged from 57.0 years for SA and Queensland to 64.8 years for NSW. These levels are more than 20 years less than those for non-Indigenous females, which were generally between 83 and 84 years.

In 2002-2006 the age-specific death rates were higher for Indigenous people than for non-Indigenous people across all age groups, but the rate ratios were particularly high in the young and middle adult years (Table 3) [1]. (These ratios, being based on the numbers of deaths registered, are likely to underestimate the true differences between death rates for Indigenous people and the total population by around 30%.)

Table 3 Indigenous and total population age-specific death rates (registered deaths) and Indigenous:non-Indigenous rate ratios, by sex, Queensland, Western Australia, South Australia, and the Northern Territory, 2001-2005

Age group (years)
Indigenous
Non-Indigenous
Rate ratio
 
Males
Females
Males
Females
Males
Females
0
15
10
5
4
3.1
2.5
1-4
71
63
27
21
2.6
2.9
5-14
30
23
12
9
2.6
2.5
15-24
194
101
73
28
2.7
3.6
25-34
422
193
102
38
4.1
5.1
35-44
836
448
137
74
6.1
6.1
45-54
1390
852
280
171
5.0
5.0
55-64
2376
1717
692
400
3.4
4.3
65+
6346
5211
4272
3672
1.5
1.4

Source: ABS, 2007 [1]

Notes:

  1. Indigenous and total population rates are for Qld, WA, SA and the NT combined
  2. Rates are infant deaths per 1,000 live births for the 0 years age group and deaths per 100,000 population for all other age groups.
  3. Rate ratio is the Indigenous rate divided by the non-Indigenous rate

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Infant mortality

The infant mortality rate 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 2004-2006, the highest Indigenous infant mortality rate was in the NT (15.6) and the lowest in NSW (8.4) (Table 4) [1]. These rates are considerably higher than those for the total population in these jurisdictions, which range from the NT (9.5) to SA (4.0).

Table 4: Infant mortality rates, Indigenous and total populations and rate ratios, selected jurisdictions, 2004-2006

Jurisdiction Indigenous Total population Rate ratio
New South Wales 7.5 4.8 1.6
Queensland 11.1 5.2 2.1
Western Australia 11.9 4.5 2.6
South Australia 6.7 3.8 1.8
Northern Territory 16.7 9.7 1.7

Source: ABS 2007 [1]

Notes:

  1. Infant mortality rate is the number of infant deaths per 1,000 live births

  2. The Indigenous rates are likely to be under-estimated, due to the incomplete identification of Indigenous status on births and deaths records

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Causes of death

For deaths identified as Indigenous in 2000-2004, cardiovascular disease (also known as ‘diseases of the circulatory system’, which includes heart disease and stroke) was the leading cause of death for Indigenous males and females living in Queensland, WA, SA and the NT (Table 5) [10]. The number of deaths recorded for Indigenous males was 3.1 times the number expected from the age-cause-specific rates for non-Indigenous males, and number recorded for Indigenous females 2.6 times the number expected from the age-cause-specific rates for non-Indigenous females. (See Box 1 for further information about these standardised mortality ratios (SMRs). The estimates quoted here have not been adjusted for the likely under-identification of Indigenous people in death registration systems, so SMRs could be up to 30% higher) [11].

For Indigenous males, the next most frequent causes of death were injuries (including transport accidents, intentional self-harm and assault) (SMR 2.8), malignant neoplasms (cancers) (SMR 1.5), diseases of the respiratory system (SMR 4.1), and endocrine, nutritional and metabolic disorders (mainly diabetes) (SMR 7.5) [10]. For Indigenous females, the most frequent causes of death after cardiovascular disease were malignant neoplasms (SMR 1.5), endocrine, nutritional and metabolic disorders (SMR 10.6), injuries (SMR 3.3), and diseases of the respiratory system (SMR 3.7).

Table 5 Indigenous:non-Indigenous standardised mortality ratios, by cause and sex, Queensland, Western Australia, South Australia and the Northern Territory, 2000-2004

Cause of death

Males

Females

 

SMR

SMR

Circulatory

3.1

2.6
Injuries

2.8

3.3
Cancer

1.5

1.5
Endocrine, nutritional and metabolic

7.5

10.6
Respiratory

4.1

3.7
Digestive

5.2

4.7
Genitourinary

4.8

7.1
Nervous system

2.6

1.6
Mental and behavioural disorders

6.0

2.5
Infectious/ parasitic

5.0

5.3
 

 

 
All causes

2.6

2.9

Source: AIHW, 2006 [10]

Notes:

  1. The standardised mortality ratio (SMR) is the ratio of the number of Indigenous deaths occurring to the number expected if the age, sex and cause-specific rates of the Australian total population applied to the Indigenous population
  2. Due to under-identification of Indigenous deaths, these numbers and SMRs are likely to underestimate the true differences between the Indigenous and non-Indigenous populations by around 30%

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Maternal mortality

In Australia in 2000-2002 (the most recent period for which detailed data are available), 13 (16.9%) of the 77 maternal deaths where Indigenous status was known were of Indigenous women (Indigenous status was not reported in 11% of the deaths) [12].

Reflecting the higher rate of confinements among Indigenous women, the maternal mortality ratio for Indigenous women in 2000-2002 was 49.9 deaths per 100,000 confinements, almost five times higher than the ratio of 9.9 per 100,000 for non-Indigenous women (Table 6) [12]. For direct maternal deaths, the ratio for Indigenous women was 15.3 compared with 3.8 for non-Indigenous women.

Table 6 Numbers of confinements, maternal deaths and maternal mortality ratios, by Indigenous status, Australia, 2000-2002

Indigenous status Confinements Maternal deaths Maternal mortality ratio
Indigenous
25,530
   
All maternal deaths  
13
  
Direct and indirect maternal deaths  
12
49.9
Non-Indigenous
758,030
   
All maternal deaths  
74
  
Direct and indirect maternal deaths  
72
9.9
`

Source: Sullivan and King (eds), 2006 [12]

Notes:

  1. Maternal mortality ratio is the number of maternal deaths divided by the number of confinements (in 100,000s). Due to some uncertainty about the numbers of Indigenous deaths and confinements, some caution must be exercised in the interpretation of the ratios
  2. The non-Indigenous numbers and ratios include deaths for which Indigenous status was not known. This probably results in a slight, unknown over-estimate, and a resultant under-estimate of the differences between Indigenous and non-Indigenous women

References

1 Australian Bureau of Statistics (2007) Deaths Australia, 2006. (ABS catalogue no. 3302.0) Canberra: Australian Bureau of Statistics

2 Australian Bureau of Statistics (2002) Deaths Australia 2001. (ABS catalogue no. 3302.0) Canberra: Australian Bureau of Statistics

3 Australian Bureau of Statistics (2003) Deaths Australia 2002. (ABS catalogue no. 3302.0) Canberra: Australian Bureau of Statistics

4 Australian Bureau of Statistics (2004) Deaths Australia 2003. (ABS catalogue no. 3302.0) Canberra: Australian Bureau of Statistics

5 Australian Bureau of Statistics (2005) Deaths Australia, 2004. (ABS catalogue no. 3302.0) Canberra: Australian Bureau of Statistics

6 Australian Bureau of Statistics (2004) Experimental estimates and projections, Aboriginal and Torres Strait Islander Australians. (ABS catalogue no. 3238.0) Canberra: Australian Bureau of Statistics

7 Australian Bureau of Statistics (2001) Deaths Australia, 2000. (ABS catalogue no. 3302.0) Canberra: Australian Bureau of Statistics

8 Australian Bureau of Statistics (2002) Australian demographic statistics quarterly: June quarter 2002. (ABS catalogue no. 3101.0) Canberra: Australian Bureau of Statistics

9 Australian Bureau of Statistics (2006) Deaths Australia, 2005. (ABS catalogue no. 3302.0) Canberra: Australian Bureau of Statistics

10 Australian Institute of Health and Welfare (2006) Australia's health 2006: the tenth biennial health report of the Australian Institute of Health and Welfare. (AIHW catalogue no. AUS 73) Canberra: Australian Institute of Health and Welfare

11 Australian Institute of Health and Welfare (2004) Australia's health 2004: the ninth biennial report of the Australian Institute of Health and Welfare. Canberra: Australian Institute of Health and Welfare

12 Sullivan EA, King JF, eds.(2006) Maternal deaths in Australia 2000-2002. Canberra: Australian Institute of Health and Welfare

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Last updated: 18 April 2008