Table 1 Number and percentage missing for each variable by centre

Age

0

0.0

0

0.0

0

0.0

Sex

2

0.0

0

0.0

0

0.0

Body mass index

341

1.8

29

0.4

1

0.0

Smoking status

114

0.6

28

0.4

1

0.0

Angina

79

0.4

15

0.2

0

0.0

Dyspnoea

93

0.5

20

0.3

0

0.0

Previous MI

54

0.3

37

0.5

10

0.2

Previous operations

15

0.1

9

0.1

0

0.0

Preoperative diabetes

75

0.4

15

0.2

0

0.0

Peripheral vascular disease

67

0.4

16

0.2

0

0.0

Pulmonary disease

65

0.4

18

0.3

0

0.0

Neurological disease

59

0.3

14

0.2

0

0.0

Hypertension

130

0.7

29

0.4

1

0.0

Haemoglobin

1,298

7.0

2,846

39.0

28

0.6

Baseline serum creatinine

282

1.5

66

0.9

19

0.4

GFR

537

2.9

86

1.2

19

0.4

Heparin or nitrates

51

0.3

18

0.3

0

0.0

Critical preoperative event

0

0.0

12

0.2

0

0.0

Catheterisation to surgery

1,447

7.7

398

5.5

242

5.0

Triple vessel disease

938

5.0

252

3.5

85

1.8

Left main stem disease

2,286

12.2

245

3.4

83

1.7

Ejection fraction

493

2.6

86

1.2

0

0.0

Operative priority

23

0.1

0

0.0

0

0.0

Cardiac procedures

0

0.0

0

0.0

0

0.0

Postoperative creatinine

282

1.5

66

0.9

84

1.7

Acute kidney injury

629

3.4

215

2.9

84

1.7

Acute kidney injury stage

629

3.4

215

2.9

84

1.7

Postoperative stay

10

0.1

0

0.0

0

0.0

Infective complication

1,564

8.4

61

0.8

96

2.0

Pulmonary complication

1,651

8.8

53

0.7

100

2.1

Died in hospital

1

0.0

6

0.1

0

0.0

Euroscore

129

0.7

48

0.7

6

0.1

Cleveland clinic score*

731

3.9

139

1.9

19

0.4

Mehta score*

369

2.0

101

1.4

29

0.6

Ng score*

613

3.3

92

1.3

20

0.4