Indigenous life expectancy using multiple Australian data sources

Professors Richard Madden and Lisa Jackson Pulver, reporting the work of Richard Madden, Lisa Jackson Pulver, Ian Ring

and Leonie Tickle

Source: Centre for Aboriginal Economic Policy Research, 2007

Source: Census of Population and Housing: Population Growth and Distribution, 2001

Australia’s Indigenous Peoples

• 2.5% of Australia’s 21.9 million people identify as Aboriginal and/or Torres Strait Islander

• Over 40% of these individuals are noted in the Medicare database as Indigenous

• Majority live in Urban areas – 25% remote• A gradient of socioeconomic disadvantage with

remoteness • Are over-represented on indicators of poor health

and socioeconomic disadvantage

Who is an Indigenous Australian?

“An Aboriginal or Torres Strait Islander is a person of Aboriginal or Torres Strait Islander descent who identifies as an Aboriginal or Torres Strait Islander and is accepted as such by the community in which he (she) lives”. Statistical definitionIndigenous Status is a measure of whether a person identifies as being of Aboriginal or Torres Strait Islander origin. This is in accord with the first two of three components of the Commonwealth definition.

6

Health data and some issues

• Under-identification in many administrative data sets is a primary problem, due to:– Historical & social factors– Different definitions over time & between data sets– Question not always asked (nor consistently)

• Extent of under-identification is not known and varies across data sets, state/territory, & time – Death registrations, Birth registrations, National

Perinatal Data collection, hospitalisations etc

Australian population 2006

Non-Indigenous deaths 2005

Indigenous Population 2006

Indigenous Deaths 2006

Systematic under estimationYear Plausible scenario Official view1788 750-800,000 300,000-1,000,000 1891 200,000 200,0001901 150,000 150,0001911 130,000 100,0001921 120,000 80,0001933 117,000 70-80,0001947 132,000 78,8171954 151,000 70,6781961 178,000 84,2701966 199,000 85,6101976 255,000 160,915 1986 325,117 250,738 1996 414,390 414,3902006 517,043 517,043Source: Madden and Jackson Pulver 2010

Development of Life Expectancy estimates

• In 1994, ‘experimental’ Indigenous population estimates introduced by Australian Bureau of Statistics (ABS)

• First indigenous life expectancy estimate in 1998, based on 1991 census:– Indirect method– Comparing 1991 and 1986 censuses

• Repeated for 1996 and 2001 census

13

New ABS direct method in 2009

• For 2006 census, ABS used a direct demographic method• Mortality rates estimated from– Indigenous deaths (numerator)– Indigenous population (denominator)

• Deaths from 7 August 2006 – 30 June 2007 were linked to census records– 92.8% Non-Indigenous records (106,945) linked– 73.7% Indigenous records (1,327) linked

Source: ABS 2009a

Consistency: the over-riding principle

ABS Key Principle ‘By aligning the deaths data to the population estimates

derived from the 2006 Census and Post Enumeration Survey, the methodology assures consistency between the numerator (that is, estimates of deaths) and the denominator (estimates of population at risk)’

In consultation, most outside the ABS argued for a second principle - both numerator and denominator need to be estimated accurately.

These two principles may be incompatible.

Life expectancy estimates at age 0

16

Male FemaleIndigenous All Gap Indigenous All Gap

1991-1996 56.9 75.2 18.3 61.7 81.1 19.4

1996-2001 59.4 76.6 17.2 64.8 82.0 17.2___________________________________________________________________ 2005-2007 67.2 78.7 11.5 72.9 82.6 9.7

ABS warning:Due to the significant changes in methodology, ABS strongly advises that comparisonsbetween the estimates presented here and previously published estimates should not be made. Differences should not be interpreted as measuring changes in Indigenous life expectancy over time.Source: ABS 2009a (and earlier similar publications)

Replacement not Ever Indigenous

What ABS did:•In linked death records, ABS replaced Indigenous identification in death records by Indigenous identification in census records•Did not use ‘Ever Indigenous’ approach: if Indigenous in either collection, then Indigenous

NSW resultsDEATH REGISTRATION classification

CENSUS Indigenous Non-Indigenous Not stated TOTALclassification No. No. No. No.

Indigenous 273 131 12 416 Non-Indigenous 87 34,460 196 34,743 Not stated 12 1,881 12 1,905 TOTAL 372 36,472 220 37,064

‘Ever Indigenous deaths’: 515 (all deaths shown in green)Source: ABS 2009a

18

Adjustment Factors by State

Indigenous deaths 9 August 2006 - 30 June 2007

Registered Estimated Increase Coverage Deaths Deaths %

NSW 372 427 14.8 87Qld 351 372 6.0 94WA 254 228 - 10.2 111NT 204 188 - 7.8 109

Australia 1,327 1,441 8.6 92

Source: ABS 2009a

2005-2007 gaps by State/Territory

Male Female CoverageNSW 8.8 7.5 87 Qld 10.4 8.9 94WA 14.0 12.5 111NT 14.4 11.9 109Australia 11.5 9.7 92

Source: ABS 2009a

Note: The order of the jurisdictions is in reverse order to the coverage estimates. Are differences between jurisdictions a data artefact?

Life expectancy differentials - Remoteness Areas, 2005-2007

Males FemalesMajor Cities 107 105Inner & outer regional 103 102Remote & very remote 90 93

Australia 100 100

Source: ABS 2009b, Table 2.16

Note: ABS assumed that under-identification of Indigenous deaths across Remoteness Areas is consistent across Australia

21

ABS option 2: Ever IndigenousIndigenous Deaths and Life Expectancy, ‘ever Indigenous’ approach

Registered Indigenous Increase Implied Life expectancy

Indigenous deaths % Coverage Male Female Deaths (‘ever Indigenous’)

NSW 453 594 31.1 76 68.3 73.6Qld 429 493 14.9 87 67.2 72.7WA 387 422 9.0 92 62.3 67.9NT 341 345 1.2 99 59.9 67.9Australia 1,800 2,123 17.9 85 66.0 71.9Source: ABS 2009a, Appendix 2

Note the more realistic coverage estimates. ABS warning: ‘This approach produces life expectancy estimates which are biased

as the identification of Indigenous status in the numerator and denominator are inconsistent.’ 22

ABS Ever Indigenous: sub-national

Comparison of Consistent and Ever Indigenous estimates

Registered Indigenous deaths Decrease in life Indigenous (‘ever Indigenous’) expectancy

Deaths & % increase Male Female

NSW 453 594 (31.1%) 1.6 1.4Qld 429 493 (14.9%) 1.1 0.9WA 387 422 (9.0%) 2.7 2.5NT 341 345 (1.2%) 1.6 1.3Aust 1,800 2,123 (17.9%) 1.2 1.0

Source: ABS 2009a

NSW ever Indigenous estimates

Linked NSW death records 2002-2006 and Admitted Patient Data collection, 2001-2006.

• 2461 registered Indigenous deaths• 3164 (28.6% increase) using ‘ever Indigenous’ rule

(ABS ever Indigenous increase was 31.1%)• 2995 (21.7 % increase) using a rule that excludes one

identification in hospital where there are multiple records• No allowance can be made for people not ever reported

Indigenous! Source: Neville, Taylor, Moore, Madden, Ring, Jackson Pulver and Tickle (in press)

NSW life expectancy estimates

ABS published ABS ever Indigenous NSW estimate

Male 72.1 69.2 69.8Female 77.2 74.6 75.2Source: Tickle and Madden, unpublished

Notes:

1 Estimates are for 2004-06 and so are not comparable to earlier tables

2 Further work is underway in NSW to identify a best practice algorithm for enhanced identification when more than two data sets are linked. Aim is to find an approach that can be used across time and across the various Australian and State data sets.

25

Life expectancy conclusion

• ABS made a major change in methodology• Large change to previous life expectancy estimates• Data used is limited: ABS data only, small numbers• ABS has announced intention to repeat census

linkage after 2011 census, and to use same methods for estimating life expectancy

• So debate and development of alternatives needs to continue

To sum up

• Aboriginal and Torres Strait Islander health issues are now receiving serious attention from statisticians

• Long history of neglect reflected community attitudes, but there were bright spots up to 1930

• There continue to be major controversies• Statistics influence, and can drive policies

We have a right to be counted – be counted or don’t count

27

References

AABS 2009a, ‘Experimental Life Tables for Aboriginal and Torres Strait Islander Australians’, cat. no.3302.0.55.003

ABS 2009b, Experimental Estimates and Projections, Aboriginal and Torres Strait Islander Australians, cat 3238.0

ABS & AIHW 2008, ‘The Health and Welfare of Australia’s Aboriginal and Torres Strait Islander Peoples’, AIHW cat. no. IHW 21

Madden, RC and Jackson Pulver, L. 2009,’ Aboriginal and Torres Strait Islander Population: More than reported’, Australian Actuarial Journal ,Vol 15 Issue 2 pp. 181 – 208

Neville, S et al, ‘Enhancement of reporting of deaths among Aboriginal and Torres Strait Islander peoples in ABS mortality data through linkage with hospital data’ (in press)

28