Multiple causes of death include all causes and conditions reported on the death certificate (i.e. both underlying and associated causes; see the Glossary of this publication for further details). As all entries on the death certificate are taken into account, multiple cause of death statistics are valuable in recognising the impact of conditions and diseases which are less likely to be an underlying cause, highlighting relationships between concurrent disease processes, and giving an indication of injuries which occur as a result of specific external events. These features of multiple cause of death data provide a more in depth picture of mortality in Australia.
When analysing data on multiple causes of death, data can be presented in two ways: by counts of deaths or counts of mentions. When analysis is conducted by counts of death, the figures are describing the number of people who have died with a particular disease/s or disorder/s. Multiple Cause of Death data derived from counts of mentions is the total number of incidences of particular disease/s or disorder/s on the death certificate. For example, an individual may have had Breast cancer (C50) and then developed Secondary lung cancer (C78.0). This individual would be counted once if counts were by the number of deaths from cancer, but twice if the counts were by the number of mentions of cancer. Care should be taken to differentiate between counts and mentions when analysing multiple cause of death data.