Table 3 Ordinary, marginal and multilevel logistic regression results: Odds ratios, OR, describing associations with 30-day mortality for patient-level and hospital-level characteristics

Patient-level

Age group (< 60 y, reference group):

60-70 y

1.5

(1.2,2.0)

1.5

(1.2-1.8)

1.5

(1.2,2.0)

70-80 y

2.7

(2.1,3.4)

2.4

(2.0-3.0)

2.7

(2.1,3.3)

80+y

3.6

(2.8,4.8)

3.3

(2.7-4.5)

3.7

(2.8,4.9)

Gender (female vs. male)

1.3

(1.1,1.6)

1.3

(1.1-1.5)

1.3

(1.1,1.6)

NYHA Class (I&II, reference group):

III

1.3

(1.1,1.6)

1.3

(1.1-1.6)

1.4

(1.1,1.6)

IV

1.7

(1.4,2.1)

1.6

(1.3-2.0)

1.7

(1.4,2.2)

Urgency of procedure (elective, reference group):

Urgent

2.0

(1.6,2.4)

1.8

(1.5-2.2)

2.0

(1.6,2.4)

Emergency/salvage

5.4

(4.3,7.0)

4.9

(4.0-6.0)

5.5

(4.3,7.0)

Ejection fraction estimate (Mild, > 45%, reference group):

Moderate (30-45%)

1.4

(1.2,1.8)

1.3

(3.0-1.6)

1.4

(1.2,1.8)

Severe (< 30%)

2.3

(1.8,2.9)

2.2

(1.8-2.7)

2.3

(1.8,2.9)

Hypercholesterolaemia

1.0

(0.8, 1.1)

1.0

(0.8-1.1)

1.0

(0.8,1.2)

Preoperative dialysis

2.2

(1.5,3.2)

2.2

(1.5-3.0)

2.2

(1.5,3.2)

Previous cardiac surgery

1.6

(1.3,2.0)

1.6

(1.3-2.0)

1.7

(1.3,2.0)

Procedure type (CABG, reference group):

Valve(s)

1.7

(1.3, 2.2)

1.6

(1.2-2.0)

1.7

(1.3, 2.2)

Valve(s)+CABG

2.2

(1.8, 2.8)

2.0

(1.6-2.6)

2.2

(1.8, 2.8)

Other

3.4

(2.7,4.1)

3.0

(2.4-3.7)

3.4

(2.8,4.2)

Inotropic medication

3.1

(2.4,3.9)

3.0

(2.4-3.7)

3.2

(2.5,4.1)

Peripheral vascular disease

1.7

(1.4,2.1)

1.6

(1.3-2.0)

1.7

(1.4,2.0)

Body mass index (25+ vs. < 25 kg/m ² )

0.8

(0.7,1.0)

0.9

(0.7-1.0)

0.8

(0.7,1.0)

Hospital-level

Academic affiliation (teaching vs. non-teaching)

1.2

(0.9,1.7)

1.2

(0.9-1.5)

1.3

(0.8,1.9)

Median of the annual number of cardiac surgeries 2001-2009, per 100 surgeries

0.88

(0.83,0.94)

0.93

(0.9-1.0)

0.91

(0.82,1.1)