Table 6 Covariate names, type, unit of measurement and additional description notes
Covariate | Type | Unit of measurement | Notes |
|---|---|---|---|
Age | Continuous | Years | Â |
Aboriginal and/or Torres Strait Islander | Binary | Yes/no | Â |
Ever diagnosed with a mental illness | Binary | Yes/no | Includes depressive, anxiety, personality, and psychotic disorders |
Ever diagnosed with a chronic health condition |  |  | Participants were classified as having a chronic health condition if they answered ‘yes’ at baseline interviews to ever having been diagnosed with a metabolic (e.g. diabetes), neurological (e.g. acquired brain injury, epilepsy), musculoskeletal (e.g. back injury, osteoarthritis), circulatory (e.g. hypertension, heart disease), respiratory condition (e.g. asthma, emphysema). Further, participants were also asked about ‘other health conditions’ at baseline; these were manually reviewed, and chronic conditions (e.g. psoriasis, gastrointestinal, cancer) reported here were also classified as chronic health conditions Infectious diseases, dental and hearing or vision conditions were not classified as, at the time of analysis, these conditions were unlikely to include routine treatment or care from general practitioners working in primary healthcare services |
Fair or poor health status | Binary | Poor or fair/good or excellent | Â |
Current accommodation unstable | Binary | Yes/no | Â |
Times moved accommodation since index release | Ordinal | 0/1 − 2/3 +  |  |
Area of residence at three-month interview | Categorical | Metropolitan/regional or rural/prison | Determined by matching self-reported residential postcode to the Australian Bureau of Statistics’ Statistical Area Codes [61]. Participants who were reimprisoned at three-month interview were classified as ‘prison’ |
Main drug injected in the preceding 30 days | Categorical | Heroin/methamphetamine/heroin and methamphetamine/neither heroin nor methamphetamine | Neither heroin nor methamphetamine is comprised of people who did not report any injecting drug use (n = 90) and people who reported injecting drugs other than heroin or methamphetamine (n = 6) in the 30 days preceding three-month follow-up interview |
Current support worker | Binary | Yes/no | Â |
12-Item General Health Questionnaire (GHQ-12) | Integer | C-GHQ-12 scoring method; range: 0–12 | The GHQ-12 is a standardised 12-item questionnaire which screens for poor psychiatric well-being over the preceding four weeks; higher scores indicate poorer psychiatric well-being condition [63, 64] |