Table 1 Baseline characteristics.

Age (years)

92.12 [90.78, 93.61]

92.07 [90.81, 93.87]

0.680

Hospital stay duration (hours)

190.38 [97.52, 328.84]

136.71 [90.93, 237.29]

< 0.001

ICU stay duration (hours)

24.25 [21.52, 28.59]

23.42 [20.50, 26.83]

0.017

Frailty score

4.00 [4.00, 6.00]

4.00 [3.00, 5.00]

0.653

Glasgow coma scale

15.00 [15.00, 15.00]

15.00 [15.00, 15.00]

>0.99

APACHE III score

56.00 [50.00, 66.00]

53.00 [47.00, 60.25]

< 0.001

SOFA score

3.00 [2.00, 5.00]

2.00 [1.00, 4.00]

< 0.001

Serum lactate (mmol/L)

1.05 [0.80, 1.50]

0.90 [0.70, 1.20]

< 0.001

Heart rate high (bpm)

85.00 [75.75, 92.00]

81.00 [75.00, 92.00]

0.296

Heart rate low (bpm)

61.50 [58.25, 70.00]

60.00 [55.00, 70.00]

0.011

Respiratory rate high (breaths/min)

22.00 [20.00, 25.00]

22.00 [20.00, 24.00]

0.813

Respiratory rate low (breaths/min)

12.00 [10.00, 15.00]

12.00 [11.00, 14.00]

0.792

Systolic BP high (mmHg)

157.00 [140.00, 170.00]

159.00 [142.00, 170.00]

0.193

Systolic BP low (mmHg)

105.00 [95.00, 120.00]

110.00 [97.75, 120.00]

0.046

Diastolic BP high (mmHg)

65.00 [60.00, 70.00]

65.00 [60.00, 72.00]

0.275

Diastolic BP low (mmHg)

45.00 [40.00, 50.00]

48.00 [40.00, 55.00]

0.009

Mean arterial pressure high (mmHg)

95.00 [88.00, 104.75]

95.00 [88.00, 105.00]

0.742

Mean arterial pressure low (mmHg)

65.00 [58.00, 73.00]

66.00 [61.00, 75.00]

0.004

Sodium high (mmol/L)

139.00 [136.50, 141.00]

139.00 [137.00, 141.00]

0.740

Sodium low (mmol/L)

137.00 [135.00, 139.00]

137.00 [135.00, 139.00]

0.180

Potassium high (mmol/L)

4.40 [4.20, 4.60]

4.30 [4.10, 4.50]

0.002

Potassium low (mmol/L)

4.10 [3.80, 4.30]

4.00 [3.70, 4.20]

0.118

Bicarbonate high (mmol/L)

25.00 [23.00, 27.00]

26.00 [24.00, 28.00]

0.090

Bicarbonate low (mmol/L)

23.25 [21.00, 26.00]

24.00 [22.00, 26.00]

0.008

Creatinine high (µmol/L)

98.00 [78.00, 123.00]

89.50 [70.00, 110.00]

0.001

Creatinine low (µmol/L)

89.00 [73.00, 111.00]

84.00 [65.00, 103.00]

0.029

Haematocrit high (%)

0.35 [0.31, 0.37]

0.34 [0.31, 0.37]

0.563

Haematocrit low (%)

0.32 [0.30, 0.35]

0.32 [0.30, 0.36]

0.377

Haemoglobin high (g/dL)

11.35 [10.38, 12.20]

11.30 [10.20, 12.40]

0.988

Haemoglobin low (g/dL)

10.60 [9.88, 11.50]

10.70 [9.65, 11.75]

0.504

White cell count high (×10^9/L)

8.40 [6.95, 11.20]

8.30 [6.95, 10.10]

0.250

White cell count low (×10^9/L)

7.13 [5.60, 9.30]

7.10 [5.90, 8.80]

0.730

Platelet count high (×10^9/L)

174.50 [135.00, 205.25]

172.00 [146.00, 210.50]

0.208

Platelet count low (×10^9/L)

156.00 [119.50, 185.00]

161.00 [133.50, 192.00]

0.111

Glucose high (mmol/L)

7.05 [6.20, 8.72]

6.60 [5.80, 7.80]

< 0.001

Glucose low (mmol/L)

5.80 [5.20, 6.70]

5.70 [5.20, 6.50]

0.117

PaO2 (mmHg)

92.00 [74.00, 117.00]

99.00 [78.00, 128.00]

0.010

PaCO2 (mmHg)

39.00 [36.00, 44.00]

40.00 [37.00, 45.00]

0.058

Arterial pH

7.40 [7.37, 7.43]

7.40 [7.37, 7.43]

0.867

Haematocrit (%)

0.32 [0.30, 0.35]

0.32 [0.30, 0.36]

0.373

Urea (mmol/L)

8.60 [6.93, 12.00]

7.70 [6.15, 9.85]

0.001

Urine output (mL)

1200.00 [897.00, 1522.50]

1230.00 [980.00, 1650.00]

0.090

Bilirubin (µmol/L)

12.00 [9.00, 17.00]

11.00 [8.00, 14.00]

0.025

Albumin (g/L)

31.00 [28.00, 33.50]

32.00 [29.75, 36.00]

< 0.001

Country

 Australia

193 (99.0)

391 (99.7)

0.257

 New Zealand

2 (1.0)

1 (0.3)

Hospital source

 Home/Hospital in the home

176 (90.3)

374 (95.4)

0.004

 Other acute hospital (not ICU/ED)

11 (5.6)

16 (4.1)

 Nursing home/Chronic care/Palliative care

3 (1.5)

2 (0.5)

 ED, other hospital

5 (2.6)

0 (0.0)

Gender

 Female

83 (42.6)

184 (46.9)

0.334

 Male

112 (57.4)

208 (53.1)

ICU source

 OT/Recovery

191 (97.9)

387 (98.7)

0.575

 Ward/Coronary care/Other HDU

3 (1.5)

2 (0.5)

 ICU, same hospital

1 (0.5)

2 (0.5)

 Direct ICU admission (from home or Hospital in the home)

0 (0.0)

1 (0.3)

Readmission

 No

192 (98.5)

391 (99.7)

0.109

 Yes

3 (1.5)

1 (0.3)

ICU mortality

 No

191 (98.5)

390 (100.0)

0.036

 Yes

3 (1.5)

0 (0.0)

Hospital mortality

 No

186 (95.4)

391 (100.0)

< 0.001

 Yes

9 (4.6)

0 (0.0)

Elective admission

 No

23 (11.8)

24 (6.1)

0.023

 Yes

172 (88.2)

368 (93.9)

Chronic respiratory disease

 No

182 (93.3)

379 (96.7)

0.086

 Yes

13 (6.7)

13 (3.3)

Chronic cardiovascular disease

 No

124 (63.6)

277 (70.7)

0.090

 Yes

71 (36.4)

115 (29.3)

Chronic liver disease

 No

195 (100.0)

392 (100.0)

NA

Chronic renal disease

 No

183 (93.8)

373 (95.2)

0.558

 Yes

12 (6.2)

19 (4.8)

Immune disease

 No

195 (100.0)

392 (100.0)

NA

Immunotherapy

 No

192 (98.5)

390 (99.5)

0.339

 Yes

3 (1.5)

2 (0.5)

AIDS

 No

195 (100.0)

392 (100.0)

NA

Hepatic failure

 No

195 (100.0)

392 (100.0)

NA

Lymphoma

 No

194 (99.5)

390 (99.5)

1.000

 Yes

1 (0.5)

2 (0.5)

Metastasis

 No

193 (99.0)

391 (99.7)

0.257

 Yes

2 (1.0)

1 (0.3)

Leukemia

 No

194 (99.5)

390 (99.5)

1.000

 Yes

1 (0.5)

2 (0.5)

Immunosuppressed

 No

192 (98.5)

390 (99.5)

0.339

 Yes

3 (1.5)

2 (0.5)

Cirrhosis

 No

195 (100.0)

392 (100.0)

NA

Treatment limitation

 Full active management (w/o treatment limitation) Treatment

191 (97.9)

387 (98.7)

0.489

 Limitation order

4 (2.1)

5 (1.3)

Delirium

 No

126 (92.0)

325 (98.8)

< 0.001

 Yes

11 (8.0)

4 (1.2)

Acute renal failure

 No

181 (98.4)

370 (98.4)

1.000

 Yes

3 (1.6)

6 (1.6)

Hospital outcome

 Died

9 (4.6)

0 (0.0)

< 0.001

 Discharged home

138 (70.8)

345 (88.2)

 Discharged to Nursing home/Chronic care/Palliative care

4 (2.1)

2 (0.5)

 ICU, other hospital

0 (0.0)

1 (0.3)

 Other acute hospital

20 (10.3)

13 (3.3)

 Rehabilitation

21 (10.8)

30 (7.7)

 Hospital in the home

2 (1.0)

0 (0.0)

 Other

1 (0.5)

0 (0.0)

ICU outcome

 Died

3 (1.5)

0 (0.0)

0.017

 Survived ICU: Home/Ward/Other

189 (97.4)

389 (99.7)

Transferred to other hospital: Other hospital – Ward

2 (1.0)

1 (0.3)

 1 month mortality

13 (6.7)

0 (0.0)

< 0.001

 6 months mortality

34 (17.4)

0 (0.0)

< 0.001

 1 year mortality

56 (28.7)

0 (0.0)

< 0.001