Limitations to analysis
Limitations in the study population
The study population does not include Australian Defence Force (ADF) members with service prior to 1 January 1985. The analysis is constrained by technical limitations in Department of Defence systems and information infrastructure for records before 1985.
Rehires
In previous years, a complex procedure was used to identify rehires between Defence personnel (PMKeyS) data extracts, and include these individuals in the ex-serving population in the time between re-hires. This was not possible this year, so it may be that the total ex-serving population is slightly underestimated.
Potential disparity due to dates mismatch between study cohort and suicide monitoring
The study population used in this report comprises of all members with ADF service since 1 January 1985, whereas suicide rates are calculated from 1997 to 2022. This gap between the beginning of the study period (1985) and the monitoring period (1997), meaning there are suicides from the period 1985 to 1996 that are not captured in this analysis.
Therefore, for the ex-serving population, there is potentially a slight bias in the suicide rate towards those who live longer (1997 onwards) for those who have served from 1985. However, the inclusion of the post-1985 cohort allows for a more complete picture of the deaths by suicide post-1997 among more of the ex-serving population. Sensitivity analysis demonstrated that the ex-serving suicide rate from 1997 to 2022 were no different when considering those who have served since 1985 compared to considering only those who have served since 1997.