Methods

Contemporary ex-serving ADF population and cohorts

The contemporary ex-serving ADF population has been identified via linkage between the Defence held Personnel Management Key Solution (PMKeyS) data and Department of Veterans’ Affairs (DVA) Clients data, see ‘Data linkage methodology and outcome’ below for details on linkage methods.

Imputation of underlying population for Concession card holders

It is not possible to determine whether a person has a concession card under the PBS within the dataset used for this report. Therefore, a concession cardholder has been identified using an individual’s dispensing information as a proxy. That is, if a person had any concessionary dispensings in the reporting year they were identified as a concession cardholder. However, this cannot be done for those contemporary ex-serving members who were not dispensed a medication in 2017–18. For these individuals, their information from 2016–17 has been used to impute the number of concession cardholders. Specifically, if a member had any concessionary dispensings in 2016–17, then in 2017–18 it is assumed they are still a concession cardholder and not a general beneficiary. Because these imputed records are for individuals with no dispensings in 2017–18, this imputation only applied to counts of underlying populations for concession card holders and general beneficiaries, and as such, these counts are estimates and a certain level of error based on this method is expected.

Rates calculations

In this report, rates have been calculated for both the contemporary ex-serving population and the Australian population. Both crude and age-sex standardised rates are calculated for the contemporary ex-serving population, and age-sex standardised rates are calculated for the Australian population.

Rates calculated for the contemporary ex-serving members in 2017–18 uses the contemporary ex-serving population as the denominator. That is, those members identified within the linked PMKeyS (Defence personnel data) and DVA client datasets who were discharged on or after 1 January 2001 and before 1 July 2017.

Rates calculated for the Australian population have use the December 2017 Australian estimated resident population (ERP) as the denominator (ABS 2018).

Age-standardised, and age-sex standardised rates have been calculated using the 2001 Australian standard populations (ABS 2018) as the weighting population. The December 2017 Australian ERP has been age-matched to the lower and upper age limits of the contemporary ex-serving population for standardised rates to make populations more comparable.

References

ABS (Australian Bureau of Statistics) 2018. Australian Demographic Statistics, December 2017. ABS cat. no. 3101.0. Canberra: ABS. Viewed 27 September 2019.