Table 1 Characteristics of the patients included in the analysis (n = 149,320)

Number

9179 (6.1)

140,141 (93.9)

149,320

Age (years), median (IQR)

77 (71.5–82.8)

75.1 (70.3–81.0)

75.2 (70.3–81.1)

Sex (men)

5674 (61.8)

80,479 (57.4)

86,153 (57.7)

Frail, yes

4142 (45.1)

37,577 (26.8)

41,719 (27.9)

Frailty score, median (IQR)

4 (3–6)

4 (3–5)

4 (3–5)

Admission diagnosis

 Cardiovascular disease

2270 (24.7)

38,456 (27.4)

40,726 (27.3)

 Gastrointestinal

1432 (15.6)

25,503 (18.2)

26,935 (18.0)

 Respiratory disease

1315 (14.3)

20,866 (14.9)

22,181 (14.8)

 Sepsis

1413 (15.4)

11,939 (8.5)

13,352 (8.9)

 Neurological disorders

735 (8.0)

11,909 (8.5)

12,644 (8.5)

 Chronic respiratory disease

1215 (13.2)

15,653 (11.2)

16,868 (11.3)

 Cardiovascular disease

1612 (17.6)

21, 883 (15.6)

23,493 (15.7)

 Chronic renal failure

578 (6.3)

6784 (4.8)

7362 (4.9)

 Chronic liver disease

189 (2.1)

1373 (0.9)

1562 (1.0)

 Immunosuppressive disease

282 (3.1)

3032 (2.2)

3314 (2.2)

 Immunosuppressive therapy

562 (6.1)

7130 (5.1)

7692 (5.1)

 Metastatic cancer

385 (4.2)

6967 (5.0)

7352 (4.9)

Hospital type

 Tertiary

3734 (40.7)

37,282 (26.6)

41,016 (27.5)

 Metropolitan

1888 (20.6)

23,697 (16.9)

25,585 (17.1)

 Rural/regional

1874 (20.4)

23,334 (16.6)

25,208 (16.9)

 Private

1683 (18.3)

55,828 (39.8)

57,511 (38.5)

 Planned admissions to ICU after elective surgery

1902 (20.7)

60,775 (43.4)

62,677 (42.0)

 APACHE III score, median (IQR), %

67 (55–82)

53 (43–66)

54 (43–67)

 APACHE III predicted mortality, mean (SD), %

25.0 (22.2)

14.3 (18.6)

15.0 (19.0)

 ANZROD, median (IQR), %

8.7 (2.6–23.9)

2.1 (0.7–8.2)

2.3 (0.7–9.1)

 ANZROD, mean (SD), %

17.2 (20.7)

9.0 (16.7)

9.5 (17.1)

ICU admission source

 Operating theatre

3638 (39.6)

82,547 (58.9)

86,185 (57.7)

 Emergency department

2846 (31.0)

31,497 (22.5)

34,343 (23.0)

 Hospital ward

1993 (21.7)

19,754 (14.1)

21,747 (14.5)

 Direct transfer from other ICU

205 (2.2)

1277 (0.9)

1482 (1.0)

 Direct admission from other hospital

472 (5.1)

4560 (3.2)

5032 (3.4)

 Direct admission from home

10 (0.1)

405 (0.3)

415 (0.3)

 Length of hospital stay, median (IQR), d

14.1 (8.2–25.0)

8.2 (4.9–14.2)

8.4 (5.0–14.9)

 Hospital mortality

1633 (17.8)

11,998 (8.6)

13,631 (9.1)