Table 2 Comparison of the delirium and non-delirium groups of the developmental cohort

Selected key variables

 Age (SD)

76.4 (6.2)

70.7 (6.8)

71.0 (6.9)

< 0.001

1.15 (1.11–1.19)

 Albumin (SD)

4.0 (0.3)

4.1 (0.3)

4.1 (0.3)

0.035

0.55 (0.31–0.96)

 Number of hypnotics and sedatives drugs (SD)

0.29 (0.62)

0.15 (0.45)

0.16 (0.46)

0.024

1.58 (1.17–2.15)

 Fall-down risk

  High

26 (29.9%)

236 (16.7%)

262 (17.5%)

0.002

2.1 (1.3–3.4)

  Low

61 (70.1%)

1,175 (83.3%)

1,236 (82.5%)

 Total number of drugs (SD)

7.4 (5.1)

5.6 (4.1)

5.7 (4.2)

< 0.001

1.09 (1.05–1.13)

 Neurologic disorders

  Y

51 (45.9%)

475 (26.1%)

526 (27.2%)

< 0.001

2.4 (1.6–3.5)

  N

60 (54.1%)

1,345 (73.9%)

1,405 (72.8%)

 Depression

  Y

17 (15.3%)

103 (5.7%)

120 (6.2%)

< 0.001

3.0 (1.7–5.2)

  N

94 (84.7%)

1,717 (94.3%)

1,811 (93.8%)

Unselected variables

 Hearing impairment

  Y

11 (10.1%)

77(4.3%)

88 (4.6%)

0.005

2.5 (1.3–4.9)

  N

98 (89.9%)

1,729 (95.7%)

1,827 (95.4%)

 The type of surgery

  UKA

2 (1.8%)

88 (4.8%)

90 (4.7%)

0.014

n.s

  TKRA

91 (82.0%)

1,572 (86.4%)

1,663 (86.1%)

  Revision- TKRA

18 (16.2%)

160 (8.8%)

178 (9.2%)

 eGFR (MDRD) (SD)

73.7 (20.9)

81.6 (21.4)

81.2 (21.5)

< 0.001

0.98 (0.97–0.99)

 Sodium (SD)

140.5 (2.6)

141.0 (2.3)

141.0 (2.4)

0.032

0.92 (0.86–0.99)

 Anticholinergic cognitive drugs burden (SD)

0.22 (0.49)

0.10 (0.36)

0.11 (0.37)

0.018

2.28 (1.76–2.95)

 Obstructive sleep apnea

  Y

3 (2.7%)

8 (0.4%)

11 (0.6%)

0.022

n.s

  N

108 (97.3%)

1,812 (99.6%)

1,920 (99.4%)

 Diabetic mellitus

  Y

45 (40.5%)

504 (27.7%)

549 (28.4%)

0.004

1.78 (1.20–2.64)

  N

66 (59.5%)

1,316 (72.3%)

1,382 (71.6%)

 AKI

  Y

4 (3.6%)

15 (0.8%)

19 (1.0%)

0.020

n.s

  N

107 (96.4%)

1,805 (99.2%)

1,912 (99.0%)

 Atrial fibrillation

  Y

13 (11.7%)

96 (5.3%)

109 (5.6%)

0.004

2.38 (1.29–4.40)

  N

98 (88.3%)

1,724 (94.7%)

1,822 (94.4%)

 Ischemic heart disease

  Y

33 (29.7%)

365 (20.1%)

398 (20.6%)

0.014

1.69 (1.10–2.57)

  N

78 (70.3%)

1,455 (79.9%)

1,533 (79.4%)

 Cerebrovascular disease

  Y

29 (26.1%)

272 (14.9%)

301 (15.6%)

0.002

2.01 (1.29–3.13)

  N

82 (73.9%)

1,548 (85.1%)

1,630 (84.4%)

 Peripheral arterial disease

  Y

24 (21.6%)

134 (7.4%)

158 (8.2%)

< 0.001

3.47 (2.14–5.64)

  N

87 (78.4%)

1,686 (92.6%)

1,773 (91.8%)

 Septic arthritis

  Y

12 (10.8%)

107 (5.9%)

119 (6.1%)

0.036

1.94 (1.03–3.64)

  N

99 (89.2%)

1,713 (94.1%)

1,812 (93.8%)