Table 3 Information of all the potential risk factors for delirium after knee and hip replacement

Age

15

0.43^a

(0.24, 0.61)

< 0.001

73.4%

11

1.15

(1.08, 1.22)

< 0.001

63.5%

Female (compared with male)

14

0.91

(0.82, 1.18)

0.851

49.0%

BMI

7

− 0.22^a

(− 0.55, 0.12)

0.207

81.4%

Education (years)

6

− 0.18^a

(− 0.35, − 0.02)

0.026

0.0%

MMSE

11

− 0.32^a

(− 0.52, − 0.13)

0.001

57.1%

Cognitive impairment

3

6.84

(3.27, 14.33)

< 0.001

0.0%

Dementia

5

3.09

(2.10, 4.56)

< 0.001

38.6%

Neurological disorders

5

2.26

(1.23, 4.15)

< 0.001

0.0%

Psychiatric illness

2

2.74

(1.34, 5.62)

0.006

0.0%

Obstructive sleep apnea

2

4.17

(1.72, 10.09)

0.002

0.0%

Knee replacement

6

1.42

(1.00, 2.02)

0.048

9.8%

Duration of surgery

7

0.29^a

(0.06, 0.52)

0.013

57.4%

Blood loss

4

0.30^a

(0.15, 0.44)

< 0.001

0.0%

Spinal anesthesia (compared with general)

5

0.62

(0.46, 0.85)

0.003

45.7%

History of cerebrovascular events

4

2.51

(1.28, 4.91)

0.007

58.4%

ASA ≥ 3

8

1.59

(1.25, 2.03)

< 0.001

29.3%

CCI

5

0.35^a

(0.04, 0.66)

0.029

56.9%

Length of stay

6

0.53^a

(0.20, 0.87)

0.002

56.7%

Total protein

2

− 0.68^a

(− 0.87, − 0.48)

< 0.001

0.0%

Albumin

2

− 0.77^a

(− 1.36, − 0.19)

0.009

71.6%

Hemoglobin

6

− 0.58^a

(− 1.11, − 0.04)

0.034

94.4%

Creatine

3

0.16^a

(− 0.00, 0.32)

0.051

0.0%

C-Reactive protein

2

0.76^a

(− 0.88, 2.41)

0.363

96.2%

Blood glucose

2

0.41^a

(− 0.67, 1.51)

0.463

91.7%

Alcohol abuse

3

0.69

(0.32, 1.46)

0.329

76.7%

Diabetic mellitus

8

1.09

(0.86, 1.40)

0.476

29.7%

Hypertension

7

1.06

(0.88, 1.29)

0.522

0.0%

Pulmonary disorders

3

1.13

(0.70, 1.82)

0.61

0.0%

Tobacco usage

3

1.22

(0.68, 2.19)

0.507

0.0%