1 No. Exposed to Allogeneic Blood (All Studies) Show forest plot

47

3857

Risk Ratio (M‐H, Random, 95% CI)

0.61 [0.53, 0.71]

2 No. Exposed to Allogeneic Blood (Transfusion Protocol) Show forest plot

47

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

2.1 Transfusion Protocol

38

2867

Risk Ratio (M‐H, Random, 95% CI)

0.63 [0.54, 0.73]

2.2 No Transfusion Protocol

9

990

Risk Ratio (M‐H, Random, 95% CI)

0.44 [0.22, 0.88]

3 No. Exposed to Allogeneic Blood (Type of Surgery) Show forest plot

47

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

3.1 Cardiac

23

1784

Risk Ratio (M‐H, Random, 95% CI)

0.77 [0.68, 0.87]

3.2 Orthopaedic

21

1887

Risk Ratio (M‐H, Random, 95% CI)

0.42 [0.32, 0.54]

3.3 Vascular

3

186

Risk Ratio (M‐H, Random, 95% CI)

0.55 [0.13, 2.36]

4 No.Exposed to Allogeneic Blood ‐ (Washed vs Unwashed) Show forest plot

47

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

4.1 Washed

21

1600

Risk Ratio (M‐H, Random, 95% CI)

0.55 [0.44, 0.68]

4.2 Unwashed

26

2174

Risk Ratio (M‐H, Random, 95% CI)

0.71 [0.60, 0.84]

5 No.Exposed to Allogeneic Blood (Timing) Show forest plot

46

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

5.1 Intra‐operative

7

564

Risk Ratio (M‐H, Random, 95% CI)

0.53 [0.35, 0.80]

5.2 Post‐operative

33

2877

Risk Ratio (M‐H, Random, 95% CI)

0.67 [0.57, 0.79]

5.3 Both Intra & Post‐operative

6

294

Risk Ratio (M‐H, Random, 95% CI)

0.57 [0.31, 1.04]

6 Units of Allogeneic Blood Transfused (All Studies) Show forest plot

27

1937

Mean Difference (IV, Random, 95% CI)

‐0.67 [‐0.89, ‐0.45]

7 Units of Allogeneic Blood Transfused (Transfusion Protocol) Show forest plot

27

Mean Difference (IV, Random, 95% CI)

Subtotals only

7.1 Transfusion Protocol

23

1544

Mean Difference (IV, Random, 95% CI)

‐0.61 [‐0.84, ‐0.37]

7.2 No Transfusion Protocol

4

393

Mean Difference (IV, Random, 95% CI)

‐1.26 [‐2.11, ‐0.40]

8 Units of Allogeneic Blood Transfused (Type of Surgery) Show forest plot

27

Mean Difference (IV, Random, 95% CI)

Subtotals only

8.1 Cardiac

17

1368

Mean Difference (IV, Random, 95% CI)

‐0.64 [‐0.90, ‐0.39]

8.2 Orthopaedic

7

383

Mean Difference (IV, Random, 95% CI)

‐0.89 [‐1.40, ‐0.39]

8.3 Vascular

3

186

Mean Difference (IV, Random, 95% CI)

0.02 [‐0.34, 0.38]

1 No. Exposed Allogeneic Blood (Cardiac) Show forest plot

23

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

1.1 Washed

9

654

Risk Ratio (M‐H, Random, 95% CI)

0.61 [0.47, 0.80]

1.2 Unwashed

14

1130

Risk Ratio (M‐H, Random, 95% CI)

0.87 [0.78, 0.97]

2 No. Exposed Allogeneic Blood (Orthopaedic) Show forest plot

21

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

2.1 Washed

9

760

Risk Ratio (M‐H, Random, 95% CI)

0.47 [0.34, 0.64]

2.2 Unwashed

12

1044

Risk Ratio (M‐H, Random, 95% CI)

0.42 [0.30, 0.60]

3 No. Exposed Allogeneic Blood (Vascular) Show forest plot

3

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

3.1 Washed

3

186

Risk Ratio (M‐H, Random, 95% CI)

0.55 [0.13, 2.36]

1 No. Exposed to Allogeneic Blood (Active vs Control) Show forest plot

28

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

1.1 Cell Salvage vs Control

28

2064

Risk Ratio (M‐H, Random, 95% CI)

0.60 [0.49, 0.73]

2 No. Exposed to Allogeneic Blood (Transfusion Protocol) Show forest plot

28

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

2.1 Transfusion Protocol

24

1674

Risk Ratio (M‐H, Random, 95% CI)

0.63 [0.52, 0.77]

2.2 No Transfusion Protocol

4

390

Risk Ratio (M‐H, Random, 95% CI)

0.27 [0.02, 4.08]

3 No. Exposed to Allogeneic Blood (Type of Surgery) Show forest plot

28

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

3.1 Cardiac

14

1029

Risk Ratio (M‐H, Random, 95% CI)

0.81 [0.70, 0.93]

3.2 Orthopaedic

11

849

Risk Ratio (M‐H, Random, 95% CI)

0.35 [0.24, 0.52]

3.3 Vascular

3

186

Risk Ratio (M‐H, Random, 95% CI)

0.55 [0.13, 2.36]

4 No. Exposed to Allogeneic Blood (Washed vs Unwashed) Show forest plot

27

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

4.1 Washed

14

1110

Risk Ratio (M‐H, Random, 95% CI)

0.53 [0.39, 0.71]

4.2 Unwashed

13

834

Risk Ratio (M‐H, Random, 95% CI)

0.73 [0.59, 0.91]

5 No. Exposed to Allogeneic Blood (Timing) Show forest plot

28

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

5.1 Intra‐operative

5

382

Risk Ratio (M‐H, Random, 95% CI)

0.61 [0.39, 0.95]

5.2 Post‐operative

18

1462

Risk Ratio (M‐H, Random, 95% CI)

0.60 [0.46, 0.79]

5.3 Both

5

220

Risk Ratio (M‐H, Random, 95% CI)

0.52 [0.28, 0.98]

6 Units Allogeneic Blood Transfused (Active vs Control) Show forest plot

18

Mean Difference (IV, Random, 95% CI)

Subtotals only

6.1 Cell Salvage vs Control

18

1260

Mean Difference (IV, Random, 95% CI)

‐0.90 [‐1.23, ‐0.56]

7 Units of Allogeneic Blood Transfused (Transfusion Protocol) Show forest plot

18

Mean Difference (IV, Random, 95% CI)

Subtotals only

7.1 Transfusion Protocol

15

969

Mean Difference (IV, Random, 95% CI)

‐0.81 [‐1.16, ‐0.46]

7.2 No Transfusion Protocol

3

291

Mean Difference (IV, Random, 95% CI)

‐1.64 [‐2.96, ‐0.33]

8 Units Allogeneic Blood Transfused (Type of Surgery) Show forest plot

18

Mean Difference (IV, Random, 95% CI)

Subtotals only

8.1 Cardiac

11

866

Mean Difference (IV, Random, 95% CI)

‐0.97 [‐1.40, ‐0.55]

8.2 Orthopaedic

4

208

Mean Difference (IV, Random, 95% CI)

‐1.13 [‐1.78, ‐0.48]

8.3 Vascular

3

186

Mean Difference (IV, Random, 95% CI)

0.02 [‐0.34, 0.38]

1 No. Exposed to Allogeneic Blood (Active vs Active) Show forest plot

20

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

1.1 Cell Salvage (Active vs Active)

20

1836

Risk Ratio (M‐H, Random, 95% CI)

0.62 [0.50, 0.77]

2 No. Exposed to Allogeneic Blood (Transfusion Protocol) Show forest plot

20

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

2.1 Transfusion Protocol

15

1236

Risk Ratio (M‐H, Random, 95% CI)

0.63 [0.50, 0.79]

2.2 No Transfusion Protocol

5

600

Risk Ratio (M‐H, Random, 95% CI)

0.59 [0.35, 1.00]

3 No. Exposed to Allogeneic Blood (Type of Surgery) Show forest plot

20

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

3.1 Cardiac

10

798

Risk Ratio (M‐H, Random, 95% CI)

0.70 [0.56, 0.87]

3.2 Orthopaedic

10

1038

Risk Ratio (M‐H, Random, 95% CI)

0.51 [0.38, 0.69]

4 No. Exposed to Allogeneic Blood (Washed vs Unwashed) Show forest plot

21

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

4.1 Washed

7

484

Risk Ratio (M‐H, Random, 95% CI)

0.54 [0.41, 0.73]

4.2 Unwashed

14

1390

Risk Ratio (M‐H, Random, 95% CI)

0.73 [0.56, 0.95]

5 No. Exposed to Allogeneic Blood (Timing) Show forest plot

21

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

5.1 Intra‐operative

3

222

Risk Ratio (M‐H, Random, 95% CI)

0.47 [0.27, 0.82]

5.2 Post‐operative

16

1535

Risk Ratio (M‐H, Random, 95% CI)

0.70 [0.55, 0.90]

5.3 Both

2

117

Risk Ratio (M‐H, Random, 95% CI)

0.71 [0.42, 1.22]

6 Units Allogeneic Blood Transfused (Active vs Active) Show forest plot

8

Mean Difference (IV, Random, 95% CI)

Subtotals only

6.1 Cell Salvage (Active vs Active)

8

627

Mean Difference (IV, Random, 95% CI)

‐0.44 [‐0.68, ‐0.19]

7 Units of Allogeneic Blood Transfused (Transfusion Protocol) Show forest plot

8

Mean Difference (IV, Random, 95% CI)

Subtotals only

7.1 Transfusion Protocol

7

525

Mean Difference (IV, Random, 95% CI)

‐0.39 [‐0.67, ‐0.12]

7.2 No Transfusion Protocol

1

102

Mean Difference (IV, Random, 95% CI)

‐0.69 [‐1.20, ‐0.18]

8 Units Allogeneic Blood Transfused (Type of Surgery) Show forest plot

8

Mean Difference (IV, Random, 95% CI)

Subtotals only

8.1 Cardiac

6

501

Mean Difference (IV, Random, 95% CI)

‐0.39 [‐0.67, ‐0.12]

8.2 Orthopaedic

2

126

Mean Difference (IV, Random, 95% CI)

‐0.69 [‐1.20, ‐0.18]

1 Total Blood Loss (All Studies) Show forest plot

23

1624

Mean Difference (IV, Random, 95% CI)

‐41.44 [‐111.57, 28.69]

2 Total Blood Loss (Active vs Control) Show forest plot

18

1168

Mean Difference (IV, Random, 95% CI)

‐32.63 [‐122.30, 57.03]

3 Total Blood Loss (Active vs Active) Show forest plot

5

456

Mean Difference (IV, Random, 95% CI)

‐61.98 [‐179.47, 55.50]

1 Language of Publication (All Studies) Show forest plot

46

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

1.1 English

41

3583

Risk Ratio (M‐H, Random, 95% CI)

0.60 [0.51, 0.71]

1.2 Non‐English

5

234

Risk Ratio (M‐H, Random, 95% CI)

0.63 [0.49, 0.82]

2 Methodological Quality (All Studies) Show forest plot

46

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

2.1 Grade B

35

2874

Risk Ratio (M‐H, Random, 95% CI)

0.64 [0.55, 0.75]

2.2 Grade C

11

918

Risk Ratio (M‐H, Random, 95% CI)

0.47 [0.28, 0.80]

1 Mortality ‐ All Studies Show forest plot

15

1212

Risk Ratio (M‐H, Random, 95% CI)

1.22 [0.55, 2.70]

2 Mortality ‐ CS vs Control Show forest plot

11

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

2.1 Cell Salvage vs Control

11

811

Risk Ratio (M‐H, Random, 95% CI)

1.53 [0.65, 3.61]

3 Mortality ‐ Active vs Active Show forest plot

4

401

Risk Ratio (M‐H, Random, 95% CI)

0.27 [0.03, 2.40]

4 Re‐operation for bleeding ‐ All Studies Show forest plot

14

1119

Risk Ratio (M‐H, Random, 95% CI)

1.00 [0.55, 1.81]

5 Re‐operation for Bleeding ‐ CS vs Control Show forest plot

8

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

5.1 Active vs Control

8

592

Risk Ratio (M‐H, Random, 95% CI)

1.08 [0.47, 2.48]

6 Re‐operation for Bleeding ‐ Active vs Active Show forest plot

6

527

Risk Ratio (M‐H, Random, 95% CI)

0.92 [0.39, 2.15]

7 Any Infection ‐ All Studies Show forest plot

13

1390

Risk Ratio (M‐H, Random, 95% CI)

0.74 [0.44, 1.25]

8 Any Infection ‐ CS vs Control Show forest plot

9

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

8.1 Cell Salvage vs Control

9

826

Risk Ratio (M‐H, Random, 95% CI)

0.75 [0.41, 1.37]

9 Any Infection ‐ Active vs Active Show forest plot

4

564

Risk Ratio (M‐H, Random, 95% CI)

0.35 [0.05, 2.63]

10 Wound Complication ‐ All Studies Show forest plot

9

730

Risk Ratio (M‐H, Random, 95% CI)

0.91 [0.46, 1.81]

11 Wound Complication ‐ CS vs Control Show forest plot

7

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

11.1 Active vs Control

7

504

Risk Ratio (M‐H, Random, 95% CI)

0.88 [0.42, 1.81]

12 Wound Complication ‐ Active vs Active Show forest plot

2

226

Risk Ratio (M‐H, Random, 95% CI)

1.24 [0.13, 11.75]

13 Any Thrombosis ‐ All Studies Show forest plot

7

497

Risk Ratio (M‐H, Random, 95% CI)

1.46 [0.56, 3.83]

14 Any Thrombosis ‐ CS vs Control Show forest plot

6

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

14.1 Active vs Control

6

379

Risk Ratio (M‐H, Random, 95% CI)

1.46 [0.56, 3.83]

15 Stroke ‐ All Studies Show forest plot

4

496

Risk Ratio (M‐H, Random, 95% CI)

0.65 [0.17, 2.50]

16 Stroke ‐ CS vs Control Show forest plot

3

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

16.1 Active vs Control

3

298

Risk Ratio (M‐H, Random, 95% CI)

0.73 [0.14, 3.72]

17 Non‐Fatal Myocardial Infarction ‐ All Studies Show forest plot

9

831

Risk Ratio (M‐H, Random, 95% CI)

0.76 [0.40, 1.43]

18 Non‐Fatal Myocardial Infarction ‐ CS vs Control Show forest plot

5

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

18.1 Active vs Control

5

448

Risk Ratio (M‐H, Random, 95% CI)

0.58 [0.28, 1.19]

19 Non‐Fatal Myocardial Infarction ‐ Active vs Active Show forest plot

4

383

Risk Ratio (M‐H, Random, 95% CI)

1.89 [0.51, 6.98]

20 Deep Vein Thrombosis (DVT) Show forest plot

4

Risk Ratio (M‐H, Random, 95% CI)

Subtotals only

20.1 Active vs Control

4

249

Risk Ratio (M‐H, Random, 95% CI)

0.93 [0.31, 2.77]

21 Hospital Length of Stay (LOS) Show forest plot

5

Mean Difference (IV, Random, 95% CI)

Subtotals only

21.1 Active vs Control

5

397

Mean Difference (IV, Random, 95% CI)

‐1.28 [‐2.65, 0.08]