Classifications and codes

Analysis of chronic conditions was based on using multiple health system data sources to provide a comprehensive picture of chronic conditions experienced by ex-serving ADF members.

Use of medications derived from PBS/RPBS data was the primary data source to identify chronic conditions. However, AIHW also included diagnoses that took place in public admitted patient care and ED care to provide a more comprehensive picture of the prevalence of chronic conditions. Diagnosis in hospital settings was based on principal and any additional diagnosis.

Most conditions were identified through the PBS/PRBS data with a small minority identified through hospital diagnoses. This pattern was consistent with previous AIHW research of chronic obstructive pulmonary disease. For more information, see Estimating the prevalence of chronic obstructive pulmonary disease using the National Integrated Health Services Information Analysis Asset.

The MBS data available for this analysis was not sufficient to indicate prevalence of chronic conditions. This was because information on the reason for encounter was not available for analysis in the MBS data.

Table 5 shows the medicines and the admitted patient care/ED diagnosis codes that were used to identify chronic conditions. Hospital codes were based on the international statistical classification of diseases Australian modification or ICD-10 AM (for more information see ICD-10-AM/ACHI/ACS Twelfth Edition. Where data was not available in this format initially it was first translated from another format such as Systematized Nomenclature of Medicine to ICD-10 AM before the analysis was completed. This translation was conducted using information from the Independent Health and Aged Care Pricing Authority.

Table 5: Codes from PBS/RPBS and admitted patient care or ED used to identify chronic conditions

Chronic conditions

PBS/RPBS

Admitted patient care or ED

Asthma/COPD

≥ 2 dispensing of R03

≥1 diagnosis of ICD10-AM: J40-J44, J45, J46

Cancer

≥ 1 dispensing of L01

≥ 1 diagnosis of ICD10-AM: C00-C97, D45, D46, D47.1, D47.3, D47.4, D47.5

Cardiovascular diseases

≥1 dispensing of B01AA, B01AC, C01, C02, C04A, C07, C08, C09

≥1 diagnosis of ICD10-AM: I00-I99

Chronic kidney disease

Nil

≥1 diagnosis of ICD10-AM: B52.0, D59.3, E10.2, E11.2, E13.2, E14.2, E85.3, I12, I13, I15.0, I15.1, T82.4, T86.1, Q60-Q63, N00-N08, N11, N12, N14-N16, N18, N19, N25-N28, N39.1, N39.2, Z49.0, Z94.0,, Z99.2

Dementia1

≥ 1 dispensing N06D

≥1 diagnosis of ICD10-AM: F00, F01, F02, F03, F05.1, F10.7, F13.7, F18.7, G30

Diabetes

≥ 2 dispensing of A10 

≥1 diagnosis of ICD10-AM: E10, E11, E13, E14, O24, O24.2, O24.3, O24.5, O24.9

Mental health conditions 

≥ 2 dispensing of N05A, N05B, N05C, N06A, N06B, N06C, N07B

≥ 1 diagnosis of ICD10-AM: F00-F99

Select musculoskeletal conditions (including arthritis, back problems, osteoporosis)

≥ 2 dispensing of M01 (except all M01AE’s and M01CA’s and M01AG01), M02, M04, M05

≥ 1 diagnosis of ICD10-AM: M05, M06, M08, M13, M15-19 M40-M43, M45-M51, M53, M54, M80-82, M85, M99

Note: PBS/RPBS codes were based on the highest practical level of the Anatomical Therapeutic Chemical Classification, and not at a level lower than the chemical subgroup.1 Dementia was based on the listed ICD10-AM codes. For the full classification of Dementia, see Table 6 below.

Medication dispensing types used to identify chronic conditions were based on Australian research adapted from a study in Switzerland to identify medicines that could be used to understand prevalence of chronic conditions (Purkiss et al. 2020). The frequency of medication that is dispensed that identifies a condition was based on research by the University of Newcastle and University of Queensland from 2020 (Dobson et al. 2020). Additional information on mental health medication was sourced from 2023 research (Chitty et al. 2023).

Hospital codes were based on a literature review (including the 2020 University of Newcastle and University of Queensland study) of previous Australian research on chronic conditions. Additional sources that were used include:

A person was considered to be living with dementia if they had any of the following dementia types.

Table 6: Dementia classification for admitted patient care and ED

Dementia type

ICD-10-AM diagnosis code

Alzheimer’s disease

F00.0, F00.1, F00.2, F00.9, G30.0, G30.1, G30.8, G30.9

Vascular dementia

F01.0, F01.1, F01.2, F01.3, F01.8, F01.9

Fronto-temporal dementia

F02.0 and G31.0

Dementia in Creutzfeldt-Jakob disease

F02.1 and A81.0

Dementia in Huntington’s disease

F02.2 and G10

Dementia in Parkinson’s disease

F02.3 and G20

Dementia in human immunodeficiency virus (HIV) disease

F02.4 and B22

Lewy Body dementia

F02.8 and G31.3

Dementia in other diseases (remainder)

F02.8 and not G31.3

F05.1 and F00.0, F00.1, F00.2, F00.9, G30.0, G30.1, G30.8, G30.9, F01.0, F01.1, F01.2, F01.3, F01.8, F01.9, F02.0, F02.1, F02.2, F02.3, F02.4, F02.8, F03, F10.7, F13.7, F18.7

Dementia due to psychoactive substance use

F10.7, F13.7, F18.7

Unspecified dementia

F03 and not F00.0, F00.1, F00.2, F00.9, G30.0, G30.1, G30.8, G30.9, F01.0, F01.1, F01.2, F01.3, F01.8, F01.9, F02.0, F02.1, F02.2, F02.3, F02.4, F02.8, F10.7, F13.7, F18.7

Delirium superimposed on dementia

F05.1 and not F00.0, F00.1, F00.2, F00.9, G30.0, G30.1, G30.8, G30.9, F01.0, F01.1, F01.2, F01.3, F01.8, F01.9, F02.0, F02.1, F02.2, F02.3, F02.4, F02.8, F03, F10.7, F13.7, F18.7

Other degenerative diseases of nervous system, not elsewhere classified

G31.1, G31.2, G31.8, G31.9 and F00.0, F00.1, F00.2, F00.9, G30.0, G30.1, G30.8, G30.9, F01.0, F01.1, F01.2, F01.3, F01.8, F01.9, F02.0, F02.1, F02.2, F02.3, F02.4, F02.8, F03, F05.1, F10.7, F13.7, F18.7

Mixed dementia

F00 and F01, F02, F10.7, F13.7, F18.7

F01 and F00, F02, F10.7, F13.7, F18.7

F02 and F00, F01, F10.7, F13.7, F18.7

F10.7 and F00, F01, F02, F13.7, F18.7

F13.7 and F00, F01, F02, F10.7, F18.7

F18.7 and F00, F01, F02, F10.7, F13.7

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