Mortality rates in Aboriginal Australians and New Zealand Maori

Dunya Tomic, Chief of Editorials and Publications PMSA

Australia and New Zealand are amongst the world leaders in terms of life expectancy. In 2012, the Australian Bureau of Statistics (ABS) determined the life expectancies at birth to be 84 years for females, and 80 years for males (1). The figures are slightly lower in New Zealand, although still very high, with a report from Statistics New Zealand in 2014 quoting life expectancy of 83 years for females and 79 years for males (2). However, as far as we have come in increasing our general national life expectancies thanking to major developments in areas including healthcare, agriculture and technology, the figures for our indigenous populations are still shockingly low, particularly in the case of Aboriginal Australians. The current gap in life expectancy between Aboriginal Australians and overall Australians is 12 years for females and up to 13 years for males according to ABS data. In New Zealand, Maori females and males are both expected to live on average 7 years less than the general New Zealand population (3).

By comparison, it is important to note that the infant mortality rates have declined for both Australian and New Zealander indigenous peoples. In Australia, the rate decreased from 22 per 1,000 live births in 1991 to 6 per 1,000 in 2012 (4). In New Zealand the rate reduced from 14 per 1,000 in 1990 to 6 per 1,000 by 2014. This shows that the current gap in life expectancy exists not due to high infant mortality rates and poor antenatal or perinatal care, but rather because of adult mortality rates resultant from non-communicable diseases, which are a substantial issue in both Aboriginal and Maori populations (5).

Despite the availability of data, comparisons between indigenous and general national populations remain difficult in Australia and New Zealand for numerous reasons including under-identification of indigenous status, and changing societal attitudes towards indigenous identification. As data from other nations including the United States and Canada has historically shown, if under-identification is greater in mortality data than in general census data, the end result is an underestimation of indigenous mortality rates (6), meaning that the life expectancy gaps may be even greater than already described.

A recent study looking at mortality trends in both Australian and New Zealand indigenous populations (7) found that although absolute mortality rates amongst Aboriginal Australians decreased substantially in the past 30 years, the life expectancy gap remained much the same. With regard to New Zealand, the gap between national and Maori life expectancy decreased gradually from the 1950s to 1990s, widening in the 1990s before again decreasing until the current day. Additionally, the greatest age group contributing to the Aboriginal life expectancy gap was the 35-59 year old group, whereas the older 60-74 year old group was the highest contributor in the Maori expectancy gap, indicating additional years of life lost among-st Aboriginal Australians. This coincides with the rising rates of premature mortality from cardiovascular disease in the Aboriginal population, particularly in males. Diabetes, chronic respiratory disease, liver cirrhosis and intentional self-harm were amongst the other major contributors to premature Aboriginal mortality rates.

In summary, both Australia and New Zealand have reduced their mortality rates over the years in their indigenous populations, however, the vast mortality gaps between the indigenous people and general national populations remain, particularly for Aboriginal Australians. Infant mortality rates have significantly been reduced indicating that the most important issue to tackle in the years to come will be the high prevalence of non-communicable disease rates in the adult indigenous populations. This will require change on a number of levels including government, community outreach, education programs, workplaces and schools. Our healthcare is evolving rapidly, which is bringing great benefits to Australia and New Zealand, so we must ensure to direct this care and use the tools we have developed to help those most in need, particularly our indigenous peoples.

References

1. Australian Bureau of Statistics: Life tables for Aboriginal and Torres Strait Islander Australians, 2010–2012. In., vol. cat no 3302.0. Canberra: ABS; 2013.

2. Statistics New Zealand. New Zealand period life tables: 2012–14. Wellington: Statistics New Zealand; 2015.

3. Statistics New Zealand. New Zealand period life tables: 2012–14. Wellington: Statistics New Zealand; 2015.

4. Australian Bureau of Statistics: Deaths, Australia, 2012. In., vol. cat no 3302.0. Canberra: ABS; 2012.

5. Tobias M, Blakely T, Matheson D, Rasanathan K, Atkinson J. Changing trends in indigenous inequalities in mortality: lessons from New Zealand. Int J Epidemiol. 2009;38:1711–22.

6. Tan L, Blakely T, Atkinson J. Ethnic counts on mortality and census data 2001-06: New Zealand census-mortality study update. N Z Med J. 2010;123(1320):37–44.

7. Phillips B, Daniels J, Woodward A, Blakely T, Taylor R, Morrell S. Mortality trends in Australian Aboriginal peoples and New Zealand Maori. Popul Health Metr. 2017;15:25.