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Life expectancy at birth
Progress and the headline indicator
People hope to have a long life, free from pain, illness or disability. Good health for all brings social and economic benefits to individuals, their families and the wider community.
An indicator describing how long Australians live while simultaneously taking into account the full burden of illness and disability, would be a desirable summary measure of progress. But although such indicators have been developed they are not available as a time series (discussed later in this commentary). Life expectancy at birth is one of the most widely used indicators of population health. It focuses on length of life rather than its quality, but it usefully summarises the health of the population.
Australian life expectancy improved during the past ten years. A boy born in 2001 could expect to live to be over 77, while a girl could expect to reach nearly 83 - increases since 1991 of three and two years respectively.
A longer term view
Increases in life expectancy occurred over most of the twentieth century, and resulted in an increase of 20 years of life for both men and women. Much of the improvement in the first part of the century was because of a decline in deaths from infectious diseases. This was associated with improvements in living conditions, such as cleaner water, better sewerage systems and improved housing, coupled with rising incomes and improved public health care, including initiatives like mass immunisation.1 These changes were particularly beneficial to infants, women who were pregnant or in childbirth, and older people; official statistics show that rapid declines in deaths among infants were the main reason that life expectancy increased in the first half of the century.2 Increases in life expectancy slowed in the middle of the twentieth century, and then plateaued in the 1960s, largely because of increases in cardiovascular disease.1
Substantial improvements in the life expectancy of older people have been a feature of the second half of the twentieth century, particularly since the 1970s. Between 1982 and 2001, life expectancy at age 70 increased by about three years for men and two and a half years for women. Life expectancy at birth over the same period increased by six years for men and just over four years for women.
Progress has been associated with a decline in deaths from chronic diseases, such as heart disease, cancer and strokes (these have replaced infectious diseases as the main causes of death). Greater attention to living healthier lifestyles, continued improvements in living standards, together with ongoing medical advances, including improvement in illness prevention, screening and diagnosis and treatment, have supported this transition.
As well as considering changes in life expectancy at birth, one can also consider changes in the proportions of people surviving to a certain age. Between 1898 to 1998, the changing proportion of the population surviving to the ages of 25, 50 and 75 increased dramatically.
At the start of the last century, 81% of men and 83% of women lived to be 25 years old. By 2001 these figures stood at 98% and 99% respectively. Over the same period the proportion of people surviving to age 50 increased from 66% and 70% to 94% and 97%, for men and women respectively. The difference between the sexes was evident throughout the period.
Change was even more rapid when one considers the proportion of the population living to be 75. In 1901 less than 25% of men and 33% of women reached their seventy-fifth birthday. By 2001 these figures stood at 67% and 80% respectively. Improvement was relatively steady over the period, except during the 1960s when the increase in some conditions, including heart disease, was enough to offset any improvements in survival rates, particularly among men older than 50.1 Since the early 1970s, the gap between men and women has closed steadily (down from over 21 percentage points in 1970 to about 12 in 2001).
Some differences within Australia
Despite continued improvement in the population's health, there are significant disparities between different groups.
Life expectancy at birth varied between the states and territories. In 2001 it was highest in the ACT for both men (79.2 years) and women (83.3 years) and lowest in the NT for both men (71.3 years) and women (76.7 years).
Men and Women
Women tend to live longer than men, and this is reflected in the differences in life expectancy throughout the twentieth century. But in recent years life expectancy at birth for men increased more quickly than for women, although a girl born in 2001 could still expect to live more than five years longer than a boy. There are a number of reasons why women live longer than men.
In 2002 death rates were higher for men than for women in all age groups. Women are thought to have a possible genetic advantage which makes them more resistant to a range of conditions.3
The remaining differences are attributed to different behavioural, lifestyle and working patterns of men and women. Women, for example, are less likely to be overweight or to smoke.4 Men are more often involved in hazardous occupations than women, while younger men in particular are more prone to risk-taking, and have higher death rates because of accidents.
Aboriginal and Torres Strait Islander Peoples
The health of many Aboriginal and Torres Strait Islander people is poor. It is difficult to assess national trends in Indigenous life expectancy because many of the historical data are of poor quality.6 What is known is that Indigenous Australians do not live as long, and that the difference is marked.
Information on Indigenous death rates in 1999-2001 are available for people living in Queensland, Western Australia, South Australia and the Northern Territory combined. Their death rates were higher than for the total population in all age groups. The largest differences were between men and women aged 35-54 (where Indigenous deaths rates were about five times higher than those of all people). In all other age groups, other than those older than 75, the Indigenous death rate was at least double that of the total population.7
A number of factors help to explain why Indigenous Australians suffer poorer health than other Australians. In general, more Indigenous Australians experience disadvantages such as poor education, unemployment, and inadequate housing and infrastructure. Indigenous Australians are more likely to smoke;4 and while several studies have shown that they are less likely to drink alcohol than other Australians, those who do are likely to consume it at hazardous levels.7 The Indigenous have high rates of infectious disease, obesity, diabetes, heart disease, kidney disease and cancer. They also experience high rates of injury and death from accidents and violence.7
Indigenous infant mortality (in Queensland, Western Australia, South Australia and the Northern Territory combined) was higher than the total infant mortality rate between 1999-2001. Indigenous infant mortality was estimated at between 16 deaths per thousand births. This is 2.6 times the rate among the total population (six deaths per 1,000 live births)7, and is similar to the level experienced by the non-Indigenous population in the mid-1970s.
ABS population projections indicate that the proportion of the population aged 65 years or more will rise. This has prompted concerns about future health care costs.
Older people are much more likely to experience ill health and disability. In 2002 just over 4% of 18-24 year-olds reported a core activity limitation, compared to nearly 36% of people aged 75 or more.8
And while Australians are living longer than ever before, there are concerns about whether the general health of older people (whether or not they are afflicted by disabilities or chronic illnesses associated with ageing) is also improving. Recent evidence is not conclusive, but it appears the length of time both men and women are living without a disability is not increasing, even though life expectancies for both are increasing.9
The burden of disease
Summary measures that combine information on mortality, disability and other non-fatal health outcomes give a more complete view of the health of the population than life expectancy alone. The most comprehensive measure in Australia has been developed by the Australian Institute of Health and Welfare (AIHW) and is known as the Disability Adjusted Life Year (DALY). It is a measure that combines information about the years of healthy life lost due either to premature mortality (relative to a standard life expectancy) and to years lived with a disability (here disability means any departure from full health, and includes conditions that range from the common cold to quadriplegia).10 The Australian burden of disease can be quantified by DALYs. In 1996 cardiovascular diseases and cancer were responsible for the loss of 547,000 and 478,000 years of healthy life, respectively. Over 85% of these years were lost due to premature mortality rather than time spent living with a disability. In contrast, almost 95% of the 338,000 years of healthy life lost to mental illness were due to years lived with a disability.
More recent data from the World Health Organisation (WHO) quantifies the non-fatal burden of disease.5 The WHO estimates healthy life expectancy in Australia was about 71.6 years in 2001, and that a boy born in 2001 can expect to spend seven years in his life with a disease or disability, while a girl can expect to spend over nine years.
BURDEN OF DISEASE(a), AUSTRALIA - 1996
Factors influencing change
Historical studies of health improvement, as well as comparisons of health between developing and developed countries, provide ample evidence that many factors have helped to improve health. In developed countries, improvements in nutrition, sanitation, water supplies, hygiene, and living and working conditions, brought major improvements in health and life expectancy, particularly before the 1950s. Advances in medical technology have also been important, especially in the past 50 years. These advances have been supported by further improvements in lifestyle such as better diet.
There is a good deal of debate about whether life expectancy will continue to increase, and there are two opposing schools of thought. Some analysts believe that there is a biological limit to an average life of around 85 years which has nearly been reached; others believe that life expectancy will continue to increase as a result of further medical advances and better lifestyles.1 There is no doubt that there is more room for improvement among some groups of the population than among others.
LEADING CAUSES OF DEATH - 2002
Causes of death
Causes of death are, of course, strongly linked to a person's age. Among people aged 1-44, transport accidents and suicide were the leading causes of death, with death rates from these causes much higher for men than for women. Among people older than 44 years, cancer and heart disease were the leading causes of death, with men again more at risk than women from these conditions.
Advances in medical technology, public health measures, including earlier detection of some illnesses, and healthier lifestyles, have contributed to declines in death rates from most of the leading causes of death. Between 1992 and 2002, death rates from cancer declined by 13% for men and over 6% for women, and death rates from heart disease declined by over 40% for men and women.
Medical experts classify deaths as avoidable and unavoidable. A potentially avoidable death is one that, theoretically, could have been avoided given current understanding of causation, and available disease prevention and health care.
One example of this is colorectal cancer, which is potentially avoidable by:
Conversely an example of a death which is not potentially avoidable is one from dementia, where no substantial gains are available through either primary, secondary or tertiary prevention with current medical technology.12
Between 1991 and 2001 the overall death rate decreased by 16% for the general population. Most of the fall was in potentially avoidable deaths, which declined by one-third (the unavoidable death rate fell by 11%). Men had a higher rate of potentially avoidable mortality than women, reflecting their higher rates of heart disease, and higher rates of death from injuries and accidents (mainly motor vehicle accidents and suicide).
Incidence and treatment of cancer and heart diseases
In 2002 cancers were the leading cause of death accounting for 28% of all deaths. Heart diseases were the second leading cause of death, contributing nearly 26% of all deaths.13 Death rates from cancer and heart disease depend in part on prevention which reduces the incidence of these diseases, and in part on how successful their treatment is.
Between 1990 and 2000 the incidence rate for all cancers (other than non-melanoma skin cancers) among men and women rose by an average of 0.5%. Over the same period, death rates from cancers fell by about 1% for both sexes.14
A significant proportion of the rise in the female incidence rate can be attributed to increases in reported breast cancer which in turn is linked to better detection of cancers by breast screening programs. Lung cancer among women is also still increasing. The rise and then fall in the male cancer rate over the period is linked to the rise and fall in reported prostate cancer.14
From 1982-1986 to 1992-1997 the percentage of cancer patients surviving 5 years or longer increased from 44% to 57% for men, and 55% to 63% for women.14
Incidence rates for all cancers(a)
Incidence rates for heart attacks (a)
Between 1993-94 and 2000-01 the incidence of heart attacks fell by 22% for men and 23% for women. The reduction in the rate of first ever heart attacks is attributed to reduced risk factors among Australians, such as smoking, high blood pressure and poor nutrition.
The reduction in the rate of heart attacks for those who have already had one is attributed to better treatment of heart disease, be it changes to health behaviour, pharmaceutical treatment or surgery. Over the same period the proportion of heart attacks that lead to death declined from 35% to 30%.
Links to other dimensions of progress
Improvements in health may assist progress in other areas and vice versa.
For instance, a healthy population stimulates economic growth: with fewer sick people to care for, more money is available for other things. While a larger pool of healthy people means a greater supply of labour for the workforce. Australian business benefits too from a healthy workforce taking fewer days off sick. Conversely the growth of the economy can help to provide funds, either to governments or individuals, to pay for better prevention programs, hospitals and health care, and to maintain suitable sanitation and housing services. Moreover, the health industry is a very significant employer and health spending accounted for about 28% of total government expenditure, and over 5% of household expenditure in 2003.20.500.
Various types of economic activity also affect human health. The burning of fossil fuels, for example, is linked to types of air pollution and a variety of health concerns. The changing make-up of the Australian economy is having an effect too: a shift to more office-based work with proportionally fewer people employed in more dangerous occupations like mining has helped,21 along with other factors, to reduce the incidence of fatal accidents at work, although more sedentary occupations have some adverse health effects.
A substantial body of evidence shows that lower socioeconomic status and less education contributes to poorer health. Likewise, poor health, particularly in childhood, can impair education and thus affect socioeconomic position in later life.22
See also the commentaries National income, The human environment, Work, and Financial hardship.