Multiple causes of death in Australia: an analysis of all natural and selected chronic disease causes of death 1997-2007

Multiple causes of death data are useful for describing the role of all diseases involved in deaths due to natural causes. This bulletin is the first comprehensive application of multiple causes of death statistics to natural causes of death and specific chronic diseases of public health importance in Australia. It may be useful for guiding and improving policy for reducing deaths from these chronic diseases and for targeting future investment in health prevention. When describing patterns of causes of death using only the underlying cause, important cause information is overlooked. Analyses using multiple cause data complement routine descriptions of mortality that use only the underlying cause and offer broader insight into the disease processes occurring at the end of life.

Key findings about multiple causes of death include:

• During the period 1997 to 2007, there were 1,442,303 deaths in Australia, with 93% due to natural causes.
• Deaths due to natural causes were not always caused by a single disease; in 2007, only 1 in 5 deaths were reported as being caused by a single disease.
• The proportion of deaths reported as being caused by five or more diseases increased from 11% in 1997 to 21% in 2007.
• In 2007, on average, 3.1 diseases contributed to each death due to natural causes.
• For younger people (aged 30-59) and for very old people (aged 95 or more), on average, fewer diseases were involved in causing their deaths than for people aged 75-94.

Key findings about multiple causes for selected chronic disease deaths include:

• Cancer was usually reported as the underlying cause of death in deaths involving cancers—in 93% for lung, 91% for liver and 84% for colorectal.
• For deaths involving chronic and unspecified kidney failure, diabetes and asthma, 17%, 29% and 30% respectively were captured in the underlying cause information.
• Coronary heart disease (CHD) was a leading contributory cause for deaths involving selected chronic diseases. It contributed to 47% of deaths involving diabetes, 39% involving chronic and unspecified kidney failure, and 34% of deaths involving each of chronic obstructive pulmonary disease (COPD) and asthma.
• Hypertensive diseases featured as a leading contributor to deaths involving selected chronic diseases, in particular diabetes (30%), cerebrovascular diseases and asthma (each 25%), CHD (20%) and chronic and unspecified kidney failure (17%).
• Diabetes was a common contributory cause, in particular for deaths involving chronic and unspecified kidney failure (20%), CHD (16%) and asthma (16%).
• Cerebrovascular diseases commonly contributed to chronic disease deaths that also involved dementia and Alzheimer disease (23%), diabetes (20%) and CHD (13%).