LIFE EXPECTANCY AT BIRTH

Transcription

1 LIFE EXPECTANCY AT BIRTH Life expectancy at birth refers to the average number of years that a group of newborn babies could expect to live if they experience the current death rates throughout their lifetime. Life expectancy at birth is one of the most widely used and internationally recognized indicators of a population s long-term health and wellbeing. KEY FIGURES LIFE EXPECTANCY AT BIRTH, NSW Male years Female Aboriginal Non-Aboriginal Difference How life expectancy is calculated Life expectancy summarises the mortality experience of a population by measuring how long, on average, a group of people born in the same year would be expected to live, if current death rates at each age remained the same. The probability of death is taken from the life tables 2 which establish the probability of death at any particular year of age, by sex. Reliable life expectancy data for Aboriginal Australians has only recently become possible, mainly due to improvements in deaths information. Life expectancy estimates are a simple average (mean) arrived at by adding up the projected years of life for every person in a birth year cohort and dividing it by the number of people born that year. Life expectancy is also calculated at each year of age. Thus, someone who is already 90 will live an extra two or three years, on average. Some of course, will live long enough to become centenarians. REMEMBER: There is no guarantee that a cohort will live to the ages specified, in the proportions predicted by current death rates. Common misconception about life expectancy Median age at death is not the same as life expectancy. The median age at death calculates the simple average of the age at death of all the people who died in the year. It thus reflects the deaths of people from many different age cohorts of past years. NOTE: Median age at death is not life expectancy. What affects life expectancy The life expectancy of Aboriginal people is potentially affected by outcomes across a wide range of areas where disadvantage is manifest. Disparities in life expectancy can be influenced by differences in income and education levels, access to high quality healthcare, social and support services, social factors, Australia Aboriginal Non-Aboriginal Difference Source: Life tables for Aboriginal and Torres Strait Islander Australians ABS Cat. No WHAT DO THE DATA SHOW? The NSW life expectancy at birth estimates for were 70.5 years for Aboriginal males and 74.6 years for Aboriginal females. Life expectancy for Aboriginal people was higher in NSW than Australia. The gap in life expectancy between Aboriginal and Non-Aboriginal people in NSW was reduced by.2 years for males (to 9.3 years), and 0. years for females (to 8.5 years) between the comparison timeframes of and Between and , life expectancy improved for both Aboriginal and Non-Aboriginal males and females in NSW. Life expectancy improved at a faster rate for Aboriginal people than Non-Aboriginal people during this time, and this resulted in a reduction in the life expectancy gap between the two groups. TERMINOLOGY Fact Sheet: Life Expectancy Estimates for Aboriginal and Torres Strait Islander Australians, released with the ABS publication of the same name, ABS Cat. No Life tables are a statistical model used to represent the mortality of a population. The term Aboriginal is used in this publication recognising that Aboriginal people are the original inhabitants of New South Wales.

2 and environmental factors, such as overcrowded housing, lack of clean drinking water and inadequate sanitation. Aboriginal life expectancy can be increased by improving access to high quality health services, greater levels of preventative care, early diagnosis of diseases (such as diabetes), more effective treatment of chronic diseases and positive health behaviours. Positive cultural, social and economic factors all help to make healthy choices viable. Alternatively, poor community functioning, poverty, disadvantage and stress can lead to unhealthy behaviours. People from lower socioeconomic groups suffer from higher rates of ill health and death at younger ages. They are also more likely to experience a larger health gap due to risk factors such as smoking, excessive alcohol consumption, illicit drug use, insufficient physical activity, and poor nutrition which, in turn, contribute to higher rates of chronic disease. Chronic diseases (for example, circulatory diseases, diabetes, kidney diseases, respiratory diseases and cancer) contribute to two thirds of the health gap (ill health and mortality) between Aboriginal and Non-Aboriginal people in Australia 3. Over time, life expectancy can be improved by the discovery of new drugs like penicillin, medical treatments like chemotherapy and by-pass surgery and environmental factors like restrictions placed on substances identified as causing serious illnesses. On the other hand, life expectancy can be adversely affected by the advent of new challenges like the spread of anti-biotic resistant bacterial diseases, new diseases like SARS, and increases in the level of obesity in the population. Proxies Because life expectancy is updated every five years, a range of variables which give some indication of where life expectancy might be heading in the interim, are used as proxies for it. All-cause mortality rates are used in the calculation of life expectancy estimates and are considered a reasonable proxy for it. Cause-specific and age-specific mortality rates are also informative. 4 Avoidable mortality and potentially preventable hospitalisations are indicators of Aboriginal people s timely and effective health care. Reducing avoidable deaths is a key component of improving Aboriginal life expectancy. 5 Prominent usages Life expectancy is one of the six Closing the Gap targets outlined in the National Indigenous Reform Agreement as well as being generally used as a proxy indicator of the overall well being of both the Aboriginal and Australian populations. LIFE EXPECTANCY AT BIRTH, BY ABORIGINALITY AND SEX, NSW AUST Female Male Female Male EXPECTED YEARS OF LIFE Aboriginal Source: Life tables for Aboriginal and Torres Strait Islander Australians ABS Cat. No HISTORICAL PERSPECTIVES Non-Aboriginal Life expectancy for Aboriginal boys born in NSW has only recently exceeded the current retirement age of 65. Data for all men in Australia 6 shows this was achieved in the 940 s and, for all women, it was the 930 s. Unfortunately, the Life expectancy for Aboriginal boys born in the Northern Territory between 200 and 202 has not yet reached the current retirement age. 3 SCRGSP (Steering Committee for the Review of Government Service Provision) 20, Overcoming Indigenous Disadvantage: Key Indicators 20, Productivity Commission, Canberra, Section 4. Life expectancy. 4 National Indigenous Reform Agreement: Performance Report for , Volume 2, Performance data, page SCRGSP 20, Section 7.3 Avoidable mortality. 6 State life expectancy estimates weren t available between the and based estimates so Australian data has been used. Data for years when both are available show that NSW and Australian data are usually quite close. Source: Australian Historical Population Statistics, 2008, ABS Cat. No , Table 7., Life expectancy at birth by sex, states and territories, 88 onwards. 2

3 Latest data L I F E E X P E C TA N C Y AT B I RT H A N D L I F E E X P E C TA N C Y AT B I RT H D I F F E R E N C E S B Y A B O R I G I N A L I T Y Jurisdictions for which life expectancy Aboriginal and Torres Non-Aboriginal Difference between estimates for Aboriginal people are Strait Islander Non-Aboriginal and available A Aboriginal life expectancy at Birth B Male Female Male Female Male Female Revised C estimate NSW Qld WA NT Australia (for State comparison) D Australia (headline rate) E estimate NSW Qld WA NT Australia (for State comparison) D Australia (headline rate) E years Source: Life tables for Aboriginal and Torres Strait Islander Australians ABS Cat. No released 5 Nov. 203 Notes: A) Life expectancy estimates for Aboriginal people are not available for Victoria, South Australia, Tasmania and the ACT as the populations of Aboriginal people who live there are too small to produce valid estimates, using current methods and data sources. B) Based on unrounded estimates. C) The figures have also been revised by the Australian Bureau of Statistics in response to data improvements, and should always replace previously released data for this period. The ABS did produce earlier estimates of life expectancy for Aboriginal Australians for the period but these estimates were too unreliable for use. After much study and follow up activities aimed at improved recording of deaths data for Aboriginal Australians, the ABS relaunched life expectancy estimates for Aboriginal Australians based on data and again, based on data. D) These estimates are not the headline estimates for Australia, because they are calculated without an age-adjustment, but are provided to enable effective comparison with state and territory estimates. E) Headline estimates for Australia are calculated using an improved methodology (taking into account age-specific identification rates) that could not be applied at the state and territory or remoteness area levels. Therefore these data should not be compared with data for any state or territory, or remoteness area. NEW DATA AVAILABLE? New life expectancy estimates will normally be developed by the ABS as one of the final releases related to the most recent census. Thus, unless there are significant developments in data quality of component datasets like deaths, the next set of estimates will be released about 2 years after the 206 census, based on deaths in

4 International comparisons : Other Anglo-settler 7 countries The comparison of life expectancy of Indigenous peoples across countries is problematic for a range of reasons, including differing methodologies, reference periods and definitions of a person s indigenous or ethnic status. There are also issues associated with the accurate measurement of deaths of indigenous persons and indigenous populations. As a result, life expectancy estimates between countries are not directly comparable. In Canada, the most recently available estimates of life expectancy are for four Inuit-inhabited areas where 80% of the combined populations of these areas are Inuit. The estimates do not distinguish between life expectancy for Inuit and non-inuit people but use total life expectancy for these areas as an overall indicator. Life expectancy at birth in Inuit-inhabited areas of Canada for 200 ( ) was 64.4 years for males and 69.8 years for females (Statistics Canada, 203). In New Zealand, a definition based on ethnicity is used in producing life tables for the Maori and non-maori populations. Ethnicity in this context relates to the ethnic group or groups that people identify with, or perceive they belong to. For , life expectancy at birth was 72.8 years for Maori males and 76.5 years for Maori females (Statistics New Zealand, 203). In the USA, the National Centre for Health Statistics publishes life tables and life expectancy estimates for black, white and all US residents but not for their First Nations peoples. Life expectancy Source: A) Statistics Canada 2008, Life Expectancy of the Inuit-inhabited areas of Canada, 989 to 2003, Health Reports, XWE, Vol. 9, No., B) Statistics New Zealand 203, New Zealand Period Life Tables, 200-2, C) United States Indian Health Service D) United States National Vital Statistics System (NVSS), CDC, NCHS, Healthy People, 200 estimates for American Indian and Alaska Native Tribes are published by the United States Indian Health Service. Life expectancy at birth for American Indian and Alaska Native Tribes was 73.5 in the period There are noticeable gaps between the life expectancy of First Nations Peoples in Canada, New Zealand and the United States Of America and the rest of their national populations. OTHER ANGLO-SETTLER COUNTRIES Country Reference Males Females Total period Canada A Canadian Inuit All Canadians New Zealand B Maori All New Zealanders United States of America American Indian and Alaska Native Tribes C Black D White D All United States residents D As described in Comparing life expectancy of Indigenous people in Australia, New Zealand, Canada and the United States, Conceptual, methodological and data issues, May 20, Australian Institute of Health and Welfare, Canberra Cat. no. IHW 47. 4

5 International comparisons 2: United Nations estimates for countries The United Nations calculates life expectancy estimates 8, using data supplied by member countries in order to report for countries, regions and for the world in total. Individual countries including Australia produce life expectancy estimates using a wide variety of methods which the UN replaces with a single method. In the case of Australia, the differences include the UN producing estimates based on five years of deaths data rather than three years used by the ABS. 9 The UN does not produce life expectancy data by Aboriginality or for regions within countries like the states and territories of Australia. However, the UN life expectancy estimate for Australians is quite close to the ABS estimate; enough to allow comparison with the ABS sourced life expectancy estimates for Aboriginal people in NSW and Australia within life expectancy bands derived from the ABS confidence intervals. A B O R I G I N A L A U S T R A L I A N S A N D U N I T E D N AT I O N S L I F E E X P E C TA N C Y E S T I M AT E S F O R C O U N T R I E S Population Life expectancy A 95% CI range UN countries comparability range B Start of range End of range NSW UN Range Aboriginal males Tonga (69.05) Montenegro (7.97) Aboriginal females Russia (73.7) El Salvador (75.89) Australia UN Range Aboriginal males Fiji (66.09) Samoa (68.62) Aboriginal females Philippines (7.29) Azerbaijan (73.4) All Australians (UN) UN Rank Males nd behind Iceland and in front of China Females th behind Japan, China, Spain, France, Switzerland and Italy Source: United Nations, Department of Economic and Social Affairs, Population Division (203). World Population Prospects: The 202 Revision, DVD Edition. Notes: A) The reference period for life expectancy estimates for Aboriginal Australians, produced by the ABS, was The reference period for life expectancy estimates produced by the United nations for all countries was B) The use of CI ranges, calculated by the ABS for its own estimates, to delineate ranges of UN produced life expectancy estimates for countries is an approximate method only. Its use is predicated on the theory that because the ABS and UN estimates for both Australian males and females are close then the CI ranges for components of the ABS produced Australian estimates will provide a reasonable guide as to the range of countries with comparable life expectancy. 8 The UN has two separate sets of life expectancy data, first, historical information from 950 to , for 20 countries for which life expectancy estimates are produced, and, second, a more restricted set of 62 countries for which life expectancy projections are produced ( through to ). Life expectancy projections are only produced for countries which have maximum adult HIV prevalence (980-20) of less than 2%. 9 The ABS notes that, because of these differences, life expectancy estimates produced by countries are not directly comparable. However, since the UN produces their life expectancy estimates on a consistent basis, country to country comparisons are acceptable. 5

6 Technical 0 The ABS used population data from the Census and Post Enumeration Survey, and death registrations data to estimate Aboriginal and Non-Aboriginal life expectancy at birth for and The ABS concluded that the indirect method used to calculate Aboriginal life expectancies was no longer adequate and that previously published estimates may have been too low (although the disparity in outcomes between Aboriginal and Non-Aboriginal people would still be substantial). However, the ABS advised that it was not possible to recalculate Aboriginal identification rates in deaths data from earlier periods. After consulting with experts and data users, the ABS developed a new method for adjusting registered Aboriginal deaths. This method used the 2006 Census Data Enhancement Aboriginal Mortality Quality Study (and equivalent from 20) data to derive factors for adjusting registered Aboriginal deaths. The adjusted deaths were then used to compile Aboriginal life tables and life expectancy estimates. Despite the ABS s efforts to improve the accuracy of Aboriginal life expectancy estimates, the underlying population and death registrations data have limitations. Therefore, life expectancy estimates are developmental and have confidence intervals that reflect these limitations. Differences between the estimated life expectancies for Aboriginal males and females, and for Aboriginal people in different states and territories should be interpreted with care. These estimates are sensitive to the demographic assumptions and differing quality of death registration data across states and territories. Further information Life expectancy trends in Australian Social Trends, March 20, ABS Cat. No ; Life tables for Aboriginal and Torres Strait Islander Australians, , ABS Cat. No released 5 Nov. 203 as well as the Fact Sheet issued under the same Cat. No. Also see Life expectancy and mortality of Aboriginal and Torres Strait Islander people, May 20, Cat. No. IHW 5, Australian Institute of Health and Welfare although the data has been superseded the explanations are useful. Data quality assessments and measures The ABS calculates sample error for Aboriginal life expectancy based on the sample error data from the Post Enumeration Survey conducted after the most recent Census. The ABS also assesses the sensitivity of the assumptions made in calculating life expectancy, especially concerning the completeness of deaths data. When combined, these two measures of data quality form the 95% confidence interval for Aboriginal life expectancy published by the ABS in Life Tables for Aboriginal and Torres Strait Islander Australians, ABS Cat. No , Appendix : Confidence Intervals in Life Tables for Aboriginal and Torres Strait Islander Australians, Enquiries Department of Education and Communities: Aboriginal Affairs, Research and Evaluation unit For more information about this or other Topic Guides john.ridley@aboriginalaffairs.nsw.gov.au or telephone (02) SCGRPS 20, Section 4. Life expectancy, page 4.6 ISSN X September 204 6