Table 4

Logistic regression modelling characteristics associated with frequent attendance: non-frequent versus (1) all frequent attenders, (2) temporary frequent attenders, (3) repeat frequent attenders and (4) persistent frequent attenders. Persons aged under 16 years

Variable	Non-frequent vs all frequent attenders*	Non-frequent vs temporary frequent attenders†	Non-frequent vs repeat frequent attenders‡	Non-frequent vs persistent frequent attenders§
Variable	OR (CI)	OR (CI)	OR (CI)	OR (CI)
Sex
Male	0.9 (0.8 to 1.1)	1.0 (0.8 to 1.2)	0.6 (0.3 to 1.0)	0.6 (0.2 to 1.4)
Female (reference)	1.0	1.0	1.0	1.0
Age group
0–4 (reference)	1.0	1.0	1.0	1.0
5–15	1.0 (0.8 to 1.2)	1.0 (0.8 to 1.1)	1.4 (0.8 to 2.4)	1.3 (0.5 to 3.1)
Uninsured (no private hospital insurance)¶
Yes	1.8 (1.4 to 2.2)	1.8 (1.4 to 2.2)	1.7 (0.8 to 3.4)	2.3 (0.7 to 7.9)
No (reference)	1.0	1.0	1.0	1.0
Aboriginal or Torres Strait Islander
Yes	1.7 (1.3 to 2.2)	1.7 (1.3 to 2.2)	1.4 (0.6 to 3.2)	1.8 (0.5 to 6.3)
No (reference)	1.0	1.0	1.0	1.0
High average triage (1–3)
Yes	2.3 (1.9 to 2.9)	2.3 (1.8 to 2.8)	2.5 (1.2 to 4.9)	4.7 (1.1 to 19.1)
No (reference)	1.0	1.0	1.0	1.0
Proportion of visits admitted	0.9 (0.7 to 1.3)	0.9 (0.6 to 1.3)	1.3 (0.5 to 3.5)	1.6 (0.3 to 8.2)
Socioeconomic status
Quintile 1 (low)	1.7 (1.4 to 2.0)	1.6 (1.3 to 2.0)	2.1 (1.2 to 3.6)	2.3 (0.9 to 5.8)
Quintile 2–5 (reference)	1.0	1.0	1.0	1.0
Major diagnostic block**
Digestive system illness	1.7 (1.3 to 2.2)	1.6 (1.2 to 2.1)	2.3 (1.0 to 5.2)	6.0 (1.4 to 24.7)
Injury, single site, major (reference)	1.0	1.0	1.0	1.0
Neurological system illness	2.7 (1.8 to 4.1)	2.4 (1.5 to 3.9)	5.0 (1.7 to 14.4)	7.6 (1.2 to 48.1)
Psychiatric illness	6.7 (4.1 to 11.1)	6.1 (3.5 to10.6)	8.6 (2.4 to 31.2)	34.7 (6.3 to 190.6)
Respiratory system illness	2.4 (1.8 to 3.0)	2.4 (1.9 to 3.0)	2.7 (1.3 to 5.9)	2.0 (0.4 to 10.2)
Other	0.9 (0.7 to 1.1)	0.9 (0.7 to 1.2)	1.2 (0.5 to 2.7)	1.4 (0.3 to 6.5)

*n=82 344, AUC=0.83, Hosmer-Lemeshow = 456 (p<0.0001), generalised χ²/DF = 0.87.
†n=82 115, AUC=0.82, Hosmer-Lemeshow = 415 (p<0.0001), generalised χ²/DF =0.85.
‡N=80 958, AUC=0.87, Hosmer-Lemeshow = 158 (p<0.0001), generalised χ²/DF =0.88.
§n=80 867, AUC=0.93, Hosmer-Lemeshow = 64 (p<0.0001), generalised χ²/DF =0.64.
¶Missing values imputed with patient’s most recent non-missing value.
**Most frequent MDB over all visits. Excludes missing diagnoses and those unable to be mapped to an MDB. All MDBs which included less than five ongoing, repeat or temporary frequent attenders was included with ‘Other MDB’ in a category labelled ‘Other’.
CI (α adjusted for multiple comparisons, 1-α/m=1–0.05/12=0.996).
AUC, area under the curve.