Suicides by length of service

Length of service describes the time between joining the ADF and separation1. For suicide rates analysis in this report, length of service is presented in five groups (ranging from less than 1 year to more than 20 years).

The proportions of ex-serving males and females by varying length of service were as follows:

  • 13.2% of males and 17.5% of females had served less than 1 year.
  • 26.1% of males and 31.8% of females had between 1-<5 years of service.
  • 18.0% of males and 21.1% of females had between 5-<10 years of service.
  • 19.0% of males and 19.0% of females had between 10-<20 years of service.
  • 23.0% of males and 10.1% of females having served 20 or more years.

The average length of service was higher for males than females (11.3 years and 7.9 years respectively).

Suicide rates for ex-serving males decreased as length of service increased. The suicide rate was lowest for males who served more than 20 years (16.5 per 100,000 population per year) and highest for those who had served less than one year (47.1 per 100,000 population per year). These are significantly different from the 1-<5, 5-<10 and 10-<20 categories, which are themselves statistically similar.

For ex-serving females, rates of suicide were statistically similar for all lengths of service. This is shown in Table 8 and Figure 12 below.

Table 8: Suicide rate by length of service, ex-serving members, 1997–2020
Length of service (years)(a) Ex-serving males: Suicide rate per 100,000 population per year Ex-serving females: Suicide rate per 100,000 population per year
<1 47.1 17.9
1-<5 33.6 16.8
5-<10 33.4 15.5
10-<20 29.1 9.8
20 or more 16.5 11.7

Notes:

  1. The time between the date of hire and date of separation from the ADF.

Source: AIHW analysis of linked Defence historical personnel data–PMKeyS–NDI data 1985–2020.

Figure 12: Suicide rate by length of service, ex-serving males and females, 1997–2020

This vertical bar graph shows the weighted average suicide rate per 100,000 population per year between 1997 and 2020 by length of service in ex-serving males and females.

Source: AIHW analysis of linked Defence historical personnel data–PMKeyS–NDI data 1985–2020.

Suicide rate by length of service over time

The suicide rates for ex-serving males by five length of service groups were relatively stable over time, apart from a large drop over the years 2004 to 2007 among the <1 year cohort. The reason for this is unknown and may be a result of low numbers. Nevertheless, this fluctuation in suicide rate was not statistically significant relative to the suicide rates over time.

Due to the small number of suicide deaths among ex-serving females, suicide rates by length of service over time are not reported.

The interactive graph below (Figure 13) presents the suicide rates for ex-serving males in each of the length of service groups, for all 3-year periods from 1997-1999 to 2018-2020.

Figure 13: Rate of suicide for ex-serving males by length of service, 1997–1999 to 2018–2020

This time series line graph shows the weighted average suicide rate per 100,000 population per year of ex-serving males by length of service over time by 3-year periods from 1997 to 1999, to 2018 to 2020.

Note: The confidence intervals in this figure can be used to determine whether there is a statistically significant difference between the suicide rates calculated for the ADF between different 3-year periods. However, they cannot be used to determine whether there is a statistically significant difference between rates calculated for the ADF population for overlapping 3-year time periods (for example 2002–2004 and 2003–2005).

Data underlying this graph are available in supplementary table S6.6. See Data for a link to the tables.

Please note, data for more recent years are subject to change; see the Technical notes for further detail.

  1. Note that the separation point used in this study reflects full separation from the ADF – that is, when a member is no longer permanent or reserve. For example, a member who transfers from full time service to the standby reserves is not yet counted as having separated.