Chronic conditions among ex-serving ADF members

Estimates of the number of people with chronic conditions can vary with the number of conditions included in the analysis, as well as the source of data used (AIHW 2024). To understand this variation AIHW compared the prevalence of chronic conditions in ex-serving members based on diagnoses through public hospitals and PBS/RPBS medication dispensing, with the prevalence that could be derived from analysis of the self-reported information collected in 2021 ABS Census.

Comparisons were made with the ex-serving population who lived in all states and territories; this was slightly different to the VHD because this data source excluded Western Australia (WA) and the Northern Territory (NT). However, analysis of Census data revealed that prevalence of chronic conditions among ex-serving members were similar for all of Australia and for Australia excluding both WA and NT.

The question in the Census asked if the person had been told by a doctor or nurse that they have any of the selected long-term health conditions (ABS 2021). Of note was that there was no time restriction in the Census question, or in other words, respondents should have indicated having a condition regardless of whether it was in remission. Therefore, the estimates of prevalence when comparing the hospital and prescription data with the Census are likely to be partly different due to how people responded and the recency of symptoms that require treatment from a chronic condition.

Additionally, there are differences in the size of the ex-serving population. The Census data included any persons who identified themselves as an ex-serving ADF member. There were almost half a million ex-serving members (496,276) based on the Census whereas AIHW analysis was limited to those who have served since 1985 and separated prior to July 2020 (227,744 as of 30 June 2020). It is possible that some persons who served in the ADF chose not to identify as ex-serving members.

Further, the age distribution of ex-serving members based on the two data sources was quite different. According to the Census, 53% of ex-serving ADF members were aged 65 years and over and only 15% were under 45 years of age. However, based on analysis of the VHD, 14% of ex-serving ADF members were aged 65 years and over and 31% were under 45 years of age in the most recent year (2019–20). This highlights that the 1985 limitation in the VHD excludes a significant cohort of older ex-serving members.

In addition to comparisons with the Census, AIHW compared results from the VHD with prevalence of chronic conditions based on the ABS National Health Survey (NHS) and the National Study of Mental Health and Wellbeing (NSMHW). AIHW reporting of chronic conditions in the Australian population is normally based on the NHS (AIHW 2024). However, for this analysis the NHS and the NSMHW were not selected because:

• The NHS and NSMHW could not be used to identify only ex-serving ADF members but rather could only be used to identify all persons who had served in the ADF at any point (which therefore included permanent, reserve and ex-serving members).
• The NHS and NSMHW had limited respondents and when breaking down chronic conditions for those who had served by age group, the results were too unreliable for use.