Characteristics of ex-serving Australian Defence Force members hospitalised for suicidality and intentional self-harm

Study period 

Data for all sources (outlined in Data sources) were available from 1 July 2010 to 30 June 2020. However, the NHDH emergency department data contained no diagnostic information for the financial years 2010–11 to 2012–13. While the entire data period was used to process the data presented, the data set used for the ED analysis was restricted to ED separations from 2013–14 to 2019–20, for which diagnostic information was available.

Study populations

The minimum age for both the ex-serving ADF and Australian populations was 17 years. 

The ex-serving ADF population in this report includes all ex-serving ADF members who have served at least one day since 1 January 1985. As of 31 December 2020, almost 379,000 Australians had served at least one day in the ADF between 1 January 1985 and 31 December 2020. Of these, just over 362,000 were still alive, comprising 60,000 permanent ADF members, 39,000 reserve ADF members, and 263,000 ex-serving ADF members. 

Public hospitals only

The ex-serving population in the study includes all ex-serving ADF members who have served at least one day since 1 January 1985, and received at least one episode of admitted patient care in a public hospital in NSW, Vic, Qld, SA, Tas or ACT and eligible DVA clients who received DVA-funded admitted patient care in a public hospital in WA or NT. 

Among this cohort, 30,700 (31.3%) were DVA clients – 8,614 (8.8%) had a DVA gold card as an indicator of eligibility for DVA-funded admitted patient care at a public or private hospital. A DVA client under the broad definition used in this report is an ex-serving member who satisfies at least one of the following criteria:

• has been issued a White, Orange or Gold card or
• had at least one accepted claim for a health or disability condition accepted as being related to ADF service or
• has received or is receiving benefits or payment or
• had at least one health service or support service through the DVA National Treatment Account.

This definition does not include veterans who had made only rejected DVA claims and were not a card holder or in receipt of any benefits from DVA (See Codes and Classifications section for more information on DVA client cards and concepts).

The difference in the age structure was reviewed – both male and female ex-serving ADF members were over-represented in the younger age groups (35-64 years). Analysis was performed at the age group level to mitigate age-related effects. The focus of this analysis was mental health – epidemiological research suggests that around half of all life-time mental disorders start by the mid-teens and three quarters by the mid-20s, with later onset disorders being mostly secondary to an existing mental disorder (Kessler et al 2007). The 2021 National Survey of Mental Health and Well-being found that the prevalence of mental disorders was highest in the 16-24 (39.6%) and 25-34 (27.1%) age groups and lowest in the 75-85 (3.7%) age group (ABS 2020-21).

According to the 2016 census data available in MADIP, 200,800 ex-serving ADF members from this cohort were living in Australia at that time – 54,500 (27.1%) in QLD, 48,600 (24.2%) in NSW, 34,000 (16.9%) in VIC, 23,600 (11.7%) in WA, 15,200 (7.5%) in SA, 7,800 (3.9%) in the ACT, 6,90 (3.4%) in TAS and 3,500 (1.7%) in the NT. 

The comparator population is the Australian population aged 17 and over. According to the 2016 census, 16,115,000 people aged 17 and over were living in Australia at that time – 3,215,000 (19.9%) in QLD, 5,151, (32.0%) in NSW, 4,100,000 (25.4%), 1,203,000 (7.5%) in SA, 1,681,000 (10.4%) in WA, 364,200 (2.3%) in TAS, 127,000 (0.8%) in NT and 275,100 (1.7%) in the ACT.

Preliminary analysis of Australian Taxation Office data found that this cohort of ex-serving ADF members had similar access to private hospital care as the Australian population in 2016 (in terms of uptake of private hospital insurance). This is consistent with previous AIHW analysis comparing related sociodemographic characteristics e.g. income, home ownership between this cohort of ex-serving ADF members and the Australian population (AIHW 2022).

Queensland public and private hospitals only

The ex-serving population for this analysis includes all ex-serving ADF members who have served at least one day since 1 January 1985, and received at least one episode of admitted patient care in a public or private hospital in Queensland.

Emergency Department care

For the ED analysis, the ex-serving population includes all ex-serving ADF members who have served at least one day since 1 January 1985, and have at least one presentation to ED in a public or private hospital in Australia. 

Limitations in the study populations

The study population does not include ADF members with service prior to 1 January 1985 due to technical limitations in Defence systems and information infrastructure for records before 1985. 

Public hospitals only

The study populations were ex-serving ADF members from this cohort and the Australian population aged 17 and over who received admitted patient care as a public or private patient in public hospitals in NSW, VIC, QLD, SA, TAS and the ACT. According to domicile recorded in the 2016 census – this means about 88% of both populations had access to a public hospital included in the NHDH data. While both populations seem to have had similar access to admitted patient care in private hospitals in terms of insurance – without complete private hospital data from all participating states and territories, it was not possible to confirm that the use of private hospital services was comparable between the two cohorts.

Additional data for admitted patient care services received by eligible ex-serving members in public hospitals in WA and NT was provided by DVA. At 1 July 2016, there were 13,100 (9% of total) gold card holders (eligible for DVA-funded admitted care) living in WA and NT. DVA Treatment Population Statistics for June 2016 are available here.

Queensland public and private hospitals only

While this analysis was more complete in terms of access and receipt of admitted patient care services, it only included about 30% of this ex-serving cohort and was restricted by small numbers.

Differences between study comparator populations

The ex-serving ADF member population for this analysis is those with 1 day of service since 1985, accordingly, the age structure is different to the total Australian population aged 17 and over. Figure 3 illustrates the differences in age structure between the ex-serving ADF and the total Australian population.

Source: AIHW analysis of linked Defence Historical Personnel data–PMKeyS–DVA client–NDI–MCD–NHMD-NNAPEDCD–MBS–PBS–RPBS data (2010–2020) and AIHW NHDH (2019-2020)

Note

• the absence of older ex-serving ADF members reflects data limitations: this cohort contains only members with service since 1985, many older ex-serving ADF members who only had service prior to 1985 are not able to be included. 
• separation from the ADF is less common at younger ages, leading to a smaller proportion of ex-serving ADF members in the 17-24 age group.
• the smaller proportion of females among the ex-serving ADF members over 64 reflects historical differences in female recruitment.

Among this cohort, ex-serving ADF members were over-represented in the 35 to 54 age groups for both admitted patient care admissions and ED presentations in comparison to the total Australian population- noting that age is related to military characteristics e.g., time served, time since service and to a lesser degree, rank. 

The differences in the age structure between the ex-serving ADF member population and the total Australian population should be considered when interpreting health-related findings. Many health conditions and diseases are directly associated with aging such as cancer, dementia and cardiovascular disease. 

However, conditions associated with suicidal behaviour such as mental and behavioural disorders, alcohol and other drug use and intentional self-harm are more prevalent among younger cohorts. Epidemiological research indicates that around half of all life-time mental and behavioural disorders emerge by mid-teens and three-quarters by the mid-20s with later onset disorders being mostly secondary to an existing mental disorder (Kessler et al 2007).

The 2021 National Survey of Mental Health and Wellbeing found that the prevalence of mental and behavioural disorders was highest in the 16 to 24 (39.6%) and 25-34 (27.1%) age groups and lowest in the 75 to 85 (3.7%) age group (ABS 2020-21). Young and middle-aged people are more likely to die by suicide than older age cohorts; almost one quarter of deaths in people aged 15 to 44 years are due to suicide (ABS 2021). Similarly, rates of hospitalisations for intentional self-harm are higher for young people (AIHW 2023).

As a result of the varying age-related health effects, this analysis has included age-specific group comparisons to control for these effects. Further, due to the differences in age structures between the ex-serving population and Australian population, AIHW recommends comparisons with the Australian population are based on age groups to control for these differences.

Where results in this analysis have been presented for comparisons between ADF member patients and the Australian population patients for “All ages 17+”, it is recommended that these results are interpreted in parallel with comparator statistics for the individual age groupings for the cohort, particularly where there are different trends, as age grouped comparisons better control for the differences in age distribution between ADF and Australian public hospital patients.