Serving and ex-serving Australian Defence Force members who have served since 1985: suicide monitoring 1997 to 2022

Changes to previously published suicide information

An additional 86 suicide deaths are reported here compared with the 2023 report. The breakdown of changes in the number of suicide deaths reported is as follows:

• 71 suicide deaths that occurred in 2022
• 15 additional suicide deaths identified in 2021 (13) and 2020 (2) due to a lag in reporting cause of death, updates to the National Death Index (NDI) or newly identified linkages.

As well as the expansion of the suicide monitoring period and addition of a new year of cause of death data, there are 3 main reasons for changes to previously published suicide results, as described below.

Lag in cause of death information

Analysis in this study is based on year of occurrence of death. The NDI is the source of information on fact of death in this study. Fact of death information from the NDI is supplemented with cause of death information from the National Mortality Database (NMD). Analysis of the NMD for all Australian deaths shows that between 4% and 7% of deaths are not registered until the next year (ABS 2018). These deaths are not captured in cause of death information, until data for the next year become available, and so there is usually a small number of suicides in each report that should have been the year prior’s data but were only confirmed after publication.

Cause of death data revisions (ABS)

Cause of death information for the Serving and ex-serving Australian Defence Force members who have served since 1985: suicide monitoring 1997 to 2022 release is based on final cause of death information for the years 1997 to 2019. Revised data are used for 2020 and preliminary data for 2021 and 2022. Cause of death for a small number of records linked to the 2020 (revised) and 2021 or 2022 (preliminary) cause of death data may change where a death is being investigated by a coroner and more up-to-date information becomes available as a result of the Australian Bureau of Statistics (ABS) revisions process. This may have a small effect on the number of deaths attributed to suicide in these years, as some deaths currently coded as ‘undetermined intent’ could later be identified as ‘intentional self-harm’ (or vice-versa).

Although this method likely captures the vast majority of suicides, there is potential for some to be missed if coronial findings take longer than 4 years and the finding results in an update to the initial coded intent of death.

Care needs to be taken when interpreting data derived from deaths registered in Victoria. Following investigations between the ABS and the Victorian Registry of Births, Deaths and Marriages, 2,812 additional registrations from 2017, 2018 and 2019 were identified that had not previously been provided to the ABS. A time series adjustment has been applied to these deaths to enable a more accurate comparison of mortality over time. Affected deaths are presented in the year in which they were registered (that is, removed from 2020 and added to 2018 or 2019). For detailed information on this issue please refer to Technical note: Victorian additional registrations and time series adjustments in Causes of death, Australia (ABS cat. no. 3303.0) available from the ABS website.

Improvements in information available to the study

Changes to previously published results may also occur as additional information becomes available to the study.

For example, differences in data collection methods and policy around timing of death registration can affect when and how the data is recorded in the ABS collection. Data users should note the potential impact of these changes when making comparisons between reference periods. While such changes will not explain all differences between years, they are a factor that may influence the magnitude of any changes in suicide numbers as revisions are applied (ABS 2018).

Improvements in available information and linkage processes over time have also resulted in additional suicides being identified for periods previously reported on.

Australian Bureau of Statistics changes to mortality coding over the study period

The following information on mortality coding is sourced from the ABS. For further information, see the ABS Causes of death, Australia report (ABS 2018).

Substantial changes to ABS cause of death coding were undertaken in 2006, improving data quality by enabling the revision of cause of death for open coroner’s cases over time. Deaths that are referred to a coroner (including deaths due to suicide) can take time to be fully investigated. To account for this, all coroner-certified deaths registered after 1 January 2006 are subject to a revisions process. This allows cause of death for open coroner’s cases to be included at a later stage where the case is closed during the revision period. Cause of death data are deemed preliminary when first published, with revised and final versions of the data being historically published 12 and 24 months after initial processing. Between 2001 and 2005, revisions did not take place and as such it is recognised by the ABS that deaths by suicide may have been understated during this period (ABS 2018).

As well as the above changes, new coding guidelines were applied to deaths registered from 1 January 2007. The new guidelines improve data quality by enabling deaths to be coded as suicide by ABS mortality coders if evidence from police reports, toxicology reports, autopsy reports and coroners’ findings indicates the death was due to suicide. Previously, coding rules required a coroner to determine a death as due to suicide for it to be coded as suicide.

The combined result of both changes has been the more complete capture of deaths by suicide, and a reduced number of deaths coded as ‘undetermined intent’, within Australian mortality data. The National Coronial Information System (NCIS) also continually makes improvements and enhancements to their system which allows for ABS coding to be accessed in a more timely fashion.

Detailed information on coding guidelines for intentional self-harm, and administrative and system changes that can have an impact on the mortality data set, can be found in Explanatory Notes 91-100 of Causes of death, Australia report (ABS 2018).