Numerous studies have estimated that the gap between indigenous and non-indigenous people‘s life expectancy in Australia is greater than in New Zealand, Canada and the United States of America (USA).
- It is now widely believed that Indigenous Australians experience lower life expectancy than their counterparts in comparable countries.
- While this may be true, there are many technical difficulties involved in estimating and comparing indigenous life expectancies. Difficulties related to concepts, data and methods behind such estimates throw doubt on conclusions drawn from country comparison studies.
Australia, New Zealand, Canada, and the USA differ in how they define indigenous, their method of operationalising the definitions, and how they adjust the death and population statistics to allow for known problems.
- New Zealand, Australia, and the USA have adopted an ‘inclusive‘ definition of indigenous; but death data are not of sufficient quality to calculate life tables in several Australian states, or in the USA as a whole. Instead the USA calculates life expectancy from data derived from the Indian Health Service.
- Canada recognises several indigenous subgroups, but they are not identified in the full Census or in the death statistics system, and special studies are used to estimate the life expectancy of some of these groups.
In general, cross–country comparisons give little or no consideration to the level of uncertainty associated with the data and methodologies used.
- Most publications present and discuss differences between country estimates of indigenous life expectancy as though they represent real differences.
- Only a few publications provide general cautions about drawing conclusions in the presence of uncertainties of largely unknown magnitude.
In the absence of direct information about estimation errors and uncertainties, this paper provides an informed evaluation of their magnitude.
- This analysis indicates that the overall uncertainty caused by conceptual, data and methodological issues could be quite large.
- Consequently, it is difficult to justify drawing many conclusions regarding cross-country differences.
Improving the reliability of comparisons would involve all countries moving towards an ‗inclusive‘ definition, and developing robust methods to test and adjust the population and death data for inadequate reporting.
- In New Zealand, Australia and the USA, only incremental change would be required: existing census and death data systems could be strengthened, and new validation and adjustment methods developed.
- In Canada, by contrast, major system changes would be required to obtain national data on the population and deaths of all the indigenous subgroups.
The International Group for Indigenous Health Measurement is an expert international working group in the field of indigenous health. With sufficient political backing, this group is appropriately placed to spearhead a coordinated international effort to overcome the barriers currently presented by the disparity between countries in concepts, data and methods underpinning indigenous life expectancy estimates.