Table 4 Transfusion frequency in different patient cohorts.

Age

≤ 66 years (median)

3/157

1.9

0.066

> 66 years (median)

9/151

6.0

< 75 years

5/217

2.3

0.026

≥ 75 years

7/91

7.7

BMI

< 28 (median)

9/155

5.8

0.081

 ≥ 28 (median)

3/153

2.0

< 30

12/196

6.1

0.008

≥ 30

0/112

0.0

ASA

≤ 2

6/238

2.5

0.02

> 2

6/69

8.7

Anticoagulation

Yes

6/87

6.9

0.088

No

6/221

2.7

Anticoagulation

No

6/221

2.7

0.001

Platelet inhibitor

2/49

4.1

DOAC

1/27

3.7

VKA

3/11

27.3

Mechanical heart valve

Yes

2/3

66.7

0.004

No

10/305

3.3

Operation

Knee arthroplasty

2/79

2.5

0.367

Hip arthroplasty

10/202

5.0

Hip arthroplasty

Standard lateral approach

8/127

6.3

0.328

Minimal invasive anterolateral approach

2/75

2.7

Drains

Yes

11/136

8.1

0.001

No

1/171

0.6

Tranexamic acid

Yes

1/118

0.8

0.029

No

11/190

5.8

Tranexamic acid

Drain

1/38

2.6

0.001

No drain

0/80

0.0

No tranexamic acid

Drain

10/98

10.2

No drain

1/91

1.1

Hemoglobin < 11.0 g/dL

Yes

4/6

66.7

< 0.001

No

8/302

2.6

Hemoglobin < 12.0 g/dl

Yes

6/26

23.1

< 0.001

No

6/282

2.1

Hemoglobin < 13.0 g/dL

Yes

10/97

10.3

< 0.001

No

2/211

0.9

Hemoglobin < 14.0 g/dL

Yes

10/165

6.1

0.035

No

2/143

1.4

GFR < 60 mL/min

Yes

3/47

6.4

0.348

No

9/258

3.5

MCHC < LLN

Yes

2/5

40.0

0.013

No

10/303

3.3