Table 1 Baseline characteristics of admitted and non-admitted patients in the derivation dataset (N = 860832)

Age (%)

<0.001

16–19 yrs

43187 (8.46)

11555 (3.30)

20–39 yrs

217827 (42.67)

72519 (20.7)

40–59 yrs

137922 (27.02)

82491 (23.54)

60–79 yrs

82207 (16.11)

105495 (30.11)

≥80 yrs

29292 (5.74)

78337 (22.36)

Male (%)

251571 (49.29)

173218 (49.43)

0.17

Indigenous (%)

21766 (4.26)

9767 (2.79)

<0.001

Nursing home (%)

3229 (0.63)

9926 (2.83)

<0.001

Ambulance arrival (%)

105123 (20.59)

181714 (51.86)

<0.001

Triage category (%)

<0.001

1

726 (0.14)

8606 (2.46)

2

43046 (8.43)

95212 (27.17)

3

156133 (30.59)

162974 (46.51)

4

242420 (47.49)

78319 (22.35)

5

68101 (13.34)

5285 (1.51)

Previous ED presentation within 7 days (%)

47144 (9.24)

32956 (9.41)

0.008

Admission within 30 days

22220 (4.35)

40997 (11.70)

<0.001

Hour of presentation (%)

<0.001

0800–1759

257400 (50.43)

189603 (54.11)

1800–2259

174097 (34.11)

106963 (30.53)

2300–0759

78938 (15.46)

53831 (15.36)

Presenting problem type (%)

<0.001

Abdominal, gastrointestinal

63630 (12.47)

60845 (17.36)

Cardiovascular

45068 (8.83)

54968 (15.69)

General symptoms

43702 (8.56)

37027 (10.57)

Febrile illness

11460 (2.25)

14522 (4.14)

Injury

106890 (20.94)

42736 (12.20)

Respiratory

19370 (3.79)

32264 (9.21)

Musculoskeletal

57727 (11.31)

20157 (5.75)

Neurological

30750 (6.02)

32569 (9.29)

Mental health

24020 (4.71)

15859 (4.53)

Toxicological

4893 (0.96)

4150 (1.18)

ENT/eye/head and neck

35014 (6.86)

5277 (1.51)

Administrative

18589 (3.64)

4282 (1.22)

Genitourinary

16318 (3.20)

11864 (3.39)

Social

302 (0.06)

310 (0.09)

Endocrine

1133 (0.22)

1903 (0.54)

Obstetrics, Gynaecology

14124 (2.77)

3675 (1.05)

Skin, allergy

17253 (3.38)

7041 (2.01)

Other medical

192 (0.04)

948 (0.27)