Table 1 Comparison between children with any PICU admission ≥28 days (long-stay) and <28 days (standard stay) up to 2 years of age

Children, n (%)

67,615 (100)

34,457 (96.0)

1,440 (4.0)

15,443 (94.5)

901 (5.5)

<0.001

3,339 (93.6)

227 (6.4)

<0.001

Postmenstrual age at first admission, median weeks (IQR)

42.3 (38.0 to 62.7)

45.3 (40.0 to 70.0)

41.3 (38.0 to 54.1)

38.3 (35.0 to 48.4)

38.3 (34.0 to 46.9)

<0.001

37.9 (29.3 to 47.4)

40.1 (31.3 to 48.4)

<0.001

Female sex, n (%)

28,477 (42.1)

14,519 (42.1)

652 (45.3)

6,421 (41.6)

368 (40.8)

0.034

1,396 (41.8)

88 (38.8)

0.065

Cumulative PICU length of stay, median days (IQR)

3.8 (1.7 to 8.0)

3.7 (1.7 to 7.2)

64.4 (43.0 to 104.9)

4.5 (2.0 to 9.1)

63.8 (43.5 to 102.3)

0.635

4.7 (1.7 to 10.8)

65.6 (44.0 to 103.8)

0.816

Cumulative length of invasive ventilation, median days (IQR)

3 (1 to 7)

3 (1 to 6)

46 (30 to 77.5)

4 (1 to 7)

45 (29 to 74)

0.747

4 (1 to 9)

48 (26 to 79)

0.568

Transfer from neonatal unit on first PICU admission, n (%)

12,528 (18.5)

5,649 (16.4)

432 (30.0)

4,723 (30.6)

467 (51.8)

<0.001

1,612 (48.3)

144 (63.4)

<0.001

Diagnostic category of first PICU admission, n (%)

 Cardiovascular

23,455 (34.7)

13,646 (39.6)

742 (51.5)

3,209 (20.8)

265 (29.4)

<0.001

642 (19.2)

37 (16.3)

<0.001

 Respiratory

20,394 (30.2)

9,352 (27.1)

345 (24.0)

6,291 (40.7)

336 (37.3)

1,209 (36.2)

118 (52.0)

 Neurological

5,660 (8.4)

3,012 (8.7)

72 (5.0)

904 (5.9)

46 (5.1)

190 (5.7)

12 (5.3)

 Gastrointestinal

5,359 (7.9)

2,251 (6.5)

64 (4.4)

2,009 (13.0)

90 (10.0)

707 (21.2)

33 (14.5)

 Infection

3,954 (5.9)

1,960 (5.7)

44 (3.1)

1,003 (6.5)

39 (4.3)

157 (4.7

10 (4.4)

 Other

8,584 (12.7)

4,157 (12.1)

169 (11.7)

1,982 (12.8)

125 (13.9)

423 (12.7)

17 (7.5)

 Missing

209 (0.3)

79 (0.2)

4 (0.3)

45 (0.3)

0

11 (0.3)

0

 PIM2 on first admission, median % (IQR)

2.2 (1.0 to 5.8)

2.3 (1.1 to 5.7)

4.9 (1.8 to 12.5)

2.1 (1.0 to 6.1)

4.2 (1.5 to 9.6)

0.004

2.8 (0.9 to 8.0)

4.5 (1.6 to 11.0)

0.362

Death within PICU

 First admission, n (%)

2,871 (4.3)

1,397 (4.1)

140 (9.7)

663 (4.3)

86 (9.5)

0.888

154 (4.6)

20 (8.8)

0.665

 Any admission, n (%)

4,224 (6.3)

1,944 (5.6)

382 (26.5)

948 (6.1)

223 (24.8)

0.339

220 (6.6)

54 (23.8)

0.383

Readmission to PICU (first admissions 2008-2016), n (%)

 >1 admission, n (%)

14,341 (25.8)

7,419 (26.5)

848 (75.7)

3,429 (27.5)

555 (76.3)

0.733

901 (33.3)

153 (80.1)

0.181

 Number of admissions, median (IQR)

1 (1 to 2)

1 (1 to 2)

3 (2 to 5)

1 (1 to 2)

3 (2 to 5)

0.677

1 (1 to 2)

3 (2 to 5)

0.823