Australian Life Expectancy

Survival adjusted probability of dying

The following calculates the probability of dying each year in the future conditional on surviving to that the start of that year.

Select a current age, to calculate the future probabilities of dying each year. Life expectancy is mostly reported from birth (age zero). The total life expectancy at a given age reflects the probability of dying over the remaining years, as the probabilities are highest in the last years of life (excepting infant mortality) life expectancy does not change substantially until a person reaches the age of 60.

The following chart compares the distribution of the probability of dying over the remaining years. The chart compares the latest distribution for 2020, with the statistics for 1970 for males and females.

Life expectancy

Life expectancy is the probability of dying a number of years in the future, it is the probability weighted sum of the survival adjustment probability of dying:

Where 0.5 is added to reflect that a person dying in a particular year is likely to die about half way through that year assuming the rates of mortality across the seasons of the year are symmetric (ie not skewed). The final probability published by the ABS is a average probability of dying over the over 100 (ie therefore 100+), a further adjustment adds the expected life of a 100 year old which under the assumptions of an exponential distribution works out to be about .

Trend life expectancy has been increasing consistently in Australia, life expectancy started accelerating in the 1970s.

International comparisons

Australia has one of the highest life expectancies. The following chart compares Australian life expectancy with the long term trends in New Zealand and the United Statess.

Expected Life for Smokers

An illustration of the impact of mortality data on life expectancy is provided below comparing predicted rates of dying from lung cancer for smokers and non-smokers. The following estimates are based on a model of the incidence of lung cancer by age adjusting for the years of smoke and the intensity of smoking (average number of cigaretts per day) published as Bates JHT, Hamlington KL, Garrison G, Kinsey CM. Prediction of lung cancer risk based on age and smoking history. Comput Methods Programs Biomed. 2022 Apr;216:106660. doi: 10.1016/j.cmpb.2022.106660, for the National Centre for Biotechnology Information in the United States.

The following compares the probability of dying of lung cancer for smokers and non-smokers. There is an underlying risk of cancer due to other environmental and genelogical risk factors which increases with age. The intensity and duration of smoking significantly increases the lung cancer risk, stopping smoking helps to prevent further increases in the risk but it never converges with the underlying non-smoker risk.

In the following chart the underlying population probability of dying (from all causes) is combined with the change in the probability of dying, by age, for smoking. Depending on the intensity and duration of smoking the risk of dying younger increases reducing the overall life expectancy of smokers.

It should be noted that lung cancer is just one of the many additional health risks from smoking. Other causes of death exacerbated by long term smoking smoking exacerbates as not captured here and would if included further reduce the life expectancy of smokers.

The differentiation for males and females reflects the significant differences in underlying population risk factors, gender is not a risk driver identified in the lung cancer risk described above.