Australian Bureau of Statistics

Rate the ABS website
ABS Home > Statistics > By Release Date
4102.0 - Australian Social Trends, 2001  
Previous ISSUE Released at 11:30 AM (CANBERRA TIME) 06/06/2001   
   Page tools: Print Print Page Print all pages in this productPrint All RSS Feed RSS Bookmark and Share Search this Product  
Contents >> Health >> Mortality and Morbidity: Mortality in the 20th century

Mortality and Morbidity: Mortality in the 20th century

During the 20th century, infectious diseases were replaced by degenerative diseases, such as heart disease and cancers, as the leading causes of deaths of Australians.

The causes of deaths, and the ages at which people die, reveal much about the health of a population. Many developed countries, including Australia, have long and well established systems which capture vital statistics including births and deaths. Death records, which can be used to generate death rates by age, sex and according to cause of death, are a commonly used indicator to measure a population's health over time.

Tasmania was the first Australian colony to adopt compulsory registration of deaths in 1839, and by the 1870s all colonies were collecting information on causes of death.1 It is therefore possible to analyse death rates in Australia for the entire 20th century.

Life expectancy in Australia increased substantially during the 20th century. In the period 1901-1910, the average life expectancy of a new-born boy was 55 years and that of a new-born girl, 59 years.2 By the end of the 20th century a new-born boy could expect to live 76 years and a new-born girl nearly 82 years (based on deaths during the period 1997-1999).3

This increase in life expectancy reflects the generally consistent decline in death rates in Australia throughout the last century. A major exception to this decline was an increase in 1919 which can largely be attributed to a global influenza epidemic. In that year, death rates from diseases of the respiratory system almost doubled for both males and females.

Death rates during the 20th century were characterised by a shift in disease patterns, (or what people were dying from) and the age at which people were dying. In the first half of the century, causes of death were dominated by infectious diseases, which tended to impact on the very young and the very old.4

From the 1950s to the 1970s, it was believed that mortality trends had reached their lower limits and that further gains would be minimal.5 However, from the early 1970s, death rates continued to decline in all age groups. Over the century, in the older age groups, degenerative diseases such as heart disease, cancer and stroke, replaced infectious diseases as the main causes of death.6


Sources and definitions
Causes of death data are compiled by the ABS from information received from State and Territory Registrars of Births, Deaths and Marriages. These data are classified according to the International Classification of Diseases (ICD).

There have been a number of revisions of the ICD during the 20th century. The first revision came into effect in 1898 and was known as the Bertillon Classification of Causes of Death.7 Subsequent revisions were as follows:
                                ICD2
-1918-1921
                                ICD3
-1922-1930
                                ICD4
-1931-1939
                                ICD5
-1940-1949
                                ICD6
-1950-1957
                                ICD7
-1958-1967
                                ICD8
-1968-1978
                                ICD9
-1979-1998
                                ICD10
-1999-
Source: AIHW Mortality Monitoring System.
Death rates are the number of deaths in a year expressed as a number per 100,000 of the population.

Age standardisation is a demographic technique used to compare estimates for populations which have different age structures. In this case it removes the effect of different age structures on death rates. Death rates in this article have been standardised to the 1991 total population.


Death rates for males and females
While death rates for both sexes declined throughout the 20th century, rates for males were consistently higher than rates for females. During the period from 1909 to 1999, the standardised death rate for males declined from 1,857 to 737 deaths per 100,000 and for females from 1,485 to 460. The declines in male and female death rates were similar during this period, although the ratio of male to female deaths converged marginally from 1.4 male deaths for every female death in the 1900s to 1.1 male deaths for every female death in the 1990s.

The exception to this trend was a divergence in the mid 1950s which continued into the 1960s and 1970s. This divergence was largely the result of increased male deaths from cancer of the trachea, bronchus and lungs, and to a lesser extent from circulatory diseases and motor vehicle accidents. The reduction in the mortality gap between the sexes later in the century can be attributed to a decline in motor vehicle accident deaths among young men, a decline in ischaemic heart disease among older men and an increase in lung cancer among older women.8

AGE STANDARDISED DEATH RATES(a)

(a) Rate per 100,000 persons.

Source: AIHW Mortality Monitoring System.


Changing age at death
One of the most notable features of 20th century death rates is the changing age at which deaths were occurring. These changes were greatest for children and the elderly.

In the first half of the century, the greatest gains were made in reducing the death rates of infants, children aged less than 5 years, and young women of child bearing age. The death rate for boys aged 0-4 years declined from nearly 2,300 per 100,000 males in 1909, to 615 in 1959, and subsequently to 149 in 1999. The pattern for females was similar, with the death rate for girls aged 0-4 years declining from approximately 2,000 deaths to less than 490 per 100,000 females in the first half of the century, to 117 deaths per 100,000 by 1999. In 1909, deaths of children aged 0-4 years comprised 24% of all deaths, whereas by 1999 this had declined to 1%.

Conversely, in the second half of the century, death rates among older persons declined the most. For example, between 1959 and 1999, the death rate for males aged 65-69 years declined by more than 50%, and a similar pattern was evident for females. This shift to a greater proportion of people living to age 65 years and over is highlighted by the fact that in 1909 approximately 31% of all deaths occurred in persons aged 65 years and over, and by 1999, this increased to 78%.

DEATH RATES(a) FOR SELECTED AGE GROUPS

Age group (years)

0-4
25-29
35-39
45-49
55-59
65-69
75-79
85+
Total
rate
rate
rate
rate
rate
rate
rate
rate
rate

Males
    1909
2,292.9
404.8
596.5
1,176.0
1,982.1
4,482.6
11,630.8
27,411.0
1,856.6
    1939
1,233.3
251.5
368.2
772.6
1,796.8
4,216.9
10,576.7
31,454.5
1,641.5
    1959
615.6
143.3
243.2
596.1
1,760.3
4,379.3
10,189.7
25,265.3
1,425.3
    1979
297.7
139.4
175.4
498.4
1,329.0
3,372.6
8,018.2
20,442.2
1,131.7
    1999
149.4
138.2
141.7
250.2
664.9
1,900.1
5,237.9
16,315.1
737.1
Females
    1909
1,913.9
428.6
629.2
822.3
1,316.6
3,474.6
9,606.5
21,977.0
1,484.7
    1939
971.2
218.4
340.9
574.7
1,104.4
3,047.3
8,257.1
27,673.9
1,253.1
    1959
483.3
71.9
158.8
403.2
876.1
2,243.9
6,598.2
22,326.8
935.8
    1979
239.4
53.1
96.2
268.8
645.2
1,602.0
4,510.9
16,317.0
659.1
    1999
117.1
42.8
70.3
163.5
383.0
993.6
3,035.1
13,451.7
460.1

(a) Rate per 100,000 persons.

Source: AIHW Mortality Monitoring System.


Causes of death
The decline in deaths from infectious diseases, particularly in the younger age groups, was the driving force behind the decline in mortality in the first half of the 20th century. In 1920, infectious diseases accounted for approximately 15% of all deaths for both males and females; the death rate for males from infectious diseases was 189 per 100,000 males, and 147 per 100,000 females. Three of the leading causes of death at this time for males aged under 5 years were infectious diseases; diarrhoea and enteritis, diphtheria and measles.

The decline in deaths from infectious diseases is generally believed to be the result of medical advances and an overall rise in living standards including improved nutrition levels, better sanitary, water and sewerage control, and better control of infection in hospitals.9

SELECTED DEATH RATES(a) FOR MALES

(a) Rate per 100,000.

Source: AIHW Mortality Monitoring System.


Death rates from infectious diseases were at their lowest in the early to mid 1980s, when the death rate for males was less than 6 per 100,000 and the rate for females was less than 4. By 1999, deaths from infectious diseases had increased to 9 males per 100,000 and 6 for females, mainly due to an increase in septicaemia-related deaths. However, infectious diseases still accounted for only 1% of all deaths in the 1990s.

As in other developed countries, as infectious diseases in Australia declined following World War I, degenerative diseases, in particular diseases of the circulatory system, began to rise as a proportion of the causes of all deaths. The emergence and dominance of diseases of the circulatory system was evident throughout most of the 20th century for both males and females, although the impact was greater for males. The age-standardised death rates for diseases of the circulatory system peaked for males in the late 1960s at 843 per 100,000, and for females in the early 1950s at 558 per 100,000.

SELECTED DEATH RATES(a) FOR FEMALES

(a) Rate per 100,000.

Source: AIHW Mortality Monitoring System.


Death rates for diseases of the circulatory system showed a significant improvement in the 1970s due in part to lifestyle changes such as a reduction in smoking (particularly among middle-aged men), and the consumption of less animal fats and increased fitness levels. In addition, there were a number of medical advances, such as improved methods of diagnosing coronary artery disease, increased use of medical services and more intensive and coronary care units.10 By 1998, the death rate for this group of diseases had declined to 285 males per 100,000 and 188 females per 100,000.

By the 1970s, cancer was a leading cause of deaths in Australia. Cancer is not a single disease but rather a collection of diseases which share the common feature of uncontrolled growth of body cells.8 Paradoxically, a greater proportion of cancer deaths in a population often reflects the higher longevity of that population, as cancer is predominantly a disease of the elderly. As a proportion of all deaths, cancer deaths increased considerably during the 20th century. In 1909, cancer accounted for 7% of all male deaths and 8% of female deaths. By 1999, cancer had increased to become the cause of approximately 27% of all deaths among both males and females.

CANCER DEATH RATES(a)

(a) Rate per 100,000.
(b) Lung cancer data only available from 1945.

Source: AIHW Mortality Monitoring System.


In 1909, the age-standardised death rate for cancer was similar for males and females (140 and 141 per 100,000). The rates for each sex began to diverge in the 1950s, and by 1985 the age-standardised male death rate from cancer was 248 compared with the female death rate of 146 per 100,000.

The rise in deaths related to male cancers during this period can largely be explained by the increase in cancers of the trachea, bronchus and lung. Tobacco smoking has been linked with 85% of male lung cancers and 55% of female lung cancers.11 Although cancer death rates for males have recently declined, there is still a large disparity between the death rates for males and females from this disease.

SELECTED CAUSES OF DEATH, 1999

Indigenous(a)
Non-Indigenous(b)


no.
%
no.
%

Cancers
281
14.2
33,832
27.7
Diabetes mellitus
128
6.5
2,762
2.3
Mental and behavioural disorders
50
2.5
2,658
2.2
Diseases of the circulatory system
603
30.5
49,155
40.2
Diseases of the respiratory system
150
7.6
9,134
7.5
Diseases of the digestive system
98
5.0
3,983
3.3
Conditions originating in the perinatal period
66
3.3
542
0.4
External causes of injury and poisoning
311
15.7
7,742
6.3
Other deaths
289
14.6
12,460
10.2
Total
1,976
100.0
122,268
100.0

(a) 1999 coverage of Indigenous deaths Australia-wide has been estimated at 85% on 1991 Census-based projections and 56% on 1996 Census-based projections.
(b) Excludes Indigenous status not stated.

Source: ABS 1999 Causes of Death.


Indigenous mortality
In 1999, there were 1,976 deaths registered where the deceased was identified as being of Aboriginal or Torres Strait Islander origin. In contrast to the non-Indigenous population, Indigenous people have lower life expectancy, higher death rates and different patterns of causes of deaths. More detailed information on the health disadvantage of Indigenous people can be found in Australian Social Trends 2000, Social conditions of Aboriginal and Torres Strait Islander people.

Indigenous life expectancy, based on experimental life tables for the period 1997-1999, indicated that Indigenous males born during this period could expect to live 56 years, 20 years less than the overall male population. An Indigenous female born in the same period could be expected to live 63 years, which was approximately 18 years less than the life expectancy of all females. Indigenous life expectancies at birth based on the period 1997-1999 are similar to those experienced by the total male population in 1901-1910 (55 years) and the total female population in 1920-1922 (63 years).

Compared with non-Indigenous deaths in 1999, a smaller proportion of Indigenous deaths were caused by cancers or diseases of the circulatory system. However, this reflects the younger age profile of the Indigenous population (using age-standardised mortality rates, Indigenous people were actually much more likely to die from these causes).11 In 1999, the proportions of Indigenous deaths from diabetes, deaths in the perinatal period and external causes of injury and poisoning, were higher than for non-Indigenous people. In the 1990s, injury and poisoning mortality rates among Indigenous people were nearly three times higher than overall rates.12


Indigenous deaths
This article includes data on Aboriginal and Torres Strait Islander deaths for all States and Territories. However, while all States and Territories have provisions in place for the identification of Indigenous deaths on their death registration forms, the undercoverage of Indigenous deaths varies greatly from State to State.


Endnotes
1 United Nations, 1982, Country monograph series no. 9, Population of Australia, Volume 1, New York.

2 Australian Bureau of Statistics 1995, Australian Social Trends, 1995, ABS cat. no. 4102.0.

3 Australian Bureau of Statistics 2000, Deaths Australia, 1999, ABS cat. no. 3302.0.

4 Omran, A.R., 1971, The epidemiologic transition, a theory of the epidemiology of population change, The Milbank Quarterly, vol.XLIX. No.4, October 1971.

5 National Population Inquiry (Australia) 1975, Population and Australia: a demographic analysis and projection (W.D. Borrie, Chairman) Australian Government Publishing Service, Canberra.

6 Olshansky, S.J., Ault, B.A., 1986, The fourth stage of the epidemiologic transition: the age of delayed degenerative diseases, The Milbank Quarterly, Vol. 64, No. 3.

7 World Health Organisation, 1977, Manual of the international statistical classification of diseases, injuries, and causes of death, Volume 1, Geneva.

8 Australian Institute of Health, 1989, Australia's Health, Australian Government Publishing Service, Canberra.

9 Australian Institute of Health and Welfare, 2000, Australia's Health, Australian Government Publishing Service, Canberra.

10 Hugo, G., 1986, Australia's changing population, trends and implications, Oxford University Press, Melbourne.

11 Australian Bureau of Statistics 1999, The Health and Welfare of Australia's Aboriginal and Torres Strait Islander Peoples, 1999, ABS cat. no. 4704.0.

12 Hetzel, D.M.S., 2001, Death, disease and diversity in Australia, 1951 to 2000, Medical Journal of Australia,. Volume 174.



Previous PageNext Page

Bookmark and Share. Opens in a new window


Commonwealth of Australia 2014

Unless otherwise noted, content on this website is licensed under a Creative Commons Attribution 2.5 Australia Licence together with any terms, conditions and exclusions as set out in the website Copyright notice. For permission to do anything beyond the scope of this licence and copyright terms contact us.