Australian cause of death data is coded to the International Classification of Diseases, 10th revision which is governed by the WHO. Case definitions, certification guidelines and coding rules have been implemented for international use.
A death directly due to COVID-19 is defined by the WHO as a death resulting from a clinically compatible illness, in a probable or confirmed COVID-19 case, unless there is a clear alternative cause of death that cannot be related to COVID disease (e.g. trauma). There should be no period of complete recovery from COVID-19 between illness and death.
In response to the emergence of COVID-19 the WHO issued new emergency codes to be used when coding causes of death for statistical purposes.
- U07.1 COVID-19 virus identified
WHO coding rules stipulate that when a country routinely tests for COVID-19, U07.1 should be assigned as the default code. In the Australian context COVID-19 may be confirmed by polymerase chain reaction (PCR) or rapid antigen testing (RAT).
- U07.2 COVID-19 virus not identified
This code is used for suspected or clinical diagnoses of COVID-19 where testing is not completed or inconclusive.
- U08 Personal history of COVID-19
This code is used when:
- A person has recovered from COVID-19 and no long term effects have been certified as contributing to an individual’s death.
- COVID-19 is listed on the death certificate but it did not contribute to the death.
These deaths are not included in COVID-19 mortality tabulations.
- U09 Post COVID-19 condition
This code is used to link long term conditions including chronic lung conditions that are the result of the virus. These deaths are included in COVID-19 mortality tabulations.
- U10 Multisystem inflammatory syndrome associated with COVID-19
This code is used to identify people who have died from a multi-inflammatory response syndrome associated with COVID-19.
A further code “Z03.8 Examination for observation and other specified reasons” can be used to record a negative test result in order to capture this information on the death certificate. These deaths are not tabulated as being due to COVID-19.
The international rules and guidance for selecting the underlying cause of death for statistical tabulation apply when COVID-19 is reported on a death certificate. COVID-19 is not considered as due to, or as an obvious consequence of, other diseases and conditions. These rules are also applied to cause of death coding for Influenza and selected other infectious diseases. There is no provision in the classification to link COVID-19 to other causes or modify its coding in any way.
Almost all deaths due to COVID-19 in Australia have confirmation of the virus through testing. Of the 15,460 registered COVID-19 deaths occurring by 31 July 2023, 15,433 (99.9%) were coded to U07.1, (confirmed) COVID-19, virus identified. There were 23 (0.1%) deaths where the doctor certified that it was a suspected case of COVID-19 with no confirmation through testing recorded at the time the MCCD was completed. There were 4 deaths that were certified as Multisystem inflammatory syndrome associated with COVID-19.