The reduction in mortality in the early part of this century has been attributed to improvements in living conditions, such as better water supply, sewage system, food quality and health education. The continuing reduction in mortality in the latter half of the century has been attributed to improving social conditions and advances in medical technology such as mass immunisation and antibiotics. The past two decades in particular have seen further increases in life expectancy. These increases are due in part to lower infant mortality, fewer deaths among young adults from motor vehicle accidents and fewer deaths among older men from heart disease. The reduction in the number of deaths from heart disease has been related to behavioural changes, such as dietary improvements, reduced smoking and increased physical activity.
Females experience an average life expectancy about six years longer than males.
At the beginning of the century, the difference between male and female life expectancy was about four years, but increased to nearly seven years by the early 1970s. This can be attributed to the large reductions in death rates of males aged 45 years and over, and particularly to the reduction in heart disease deaths among males. Australians have an average life expectancy which compares well with that experienced in other developed nations. Life expectancy in Australia was higher than in New Zealand, the United Kingdom and the United States of America. The standardised death rate removes the effect of different age structures of the population on the crude death rates.