Table 2 Association between covariates and 30-day mortality

Type of transfer

 Repatriation

Reference

Reference

 Clinical transfer

0.88

0.78–1.00

1.17

1.02–1.36

 Capacity transfer

1.72

1.48–2.00

1.25

1.06–1.49

Variables adjusted for

 Age (per year)

1.04

1.04–1.05

1.04

1.04–1.05

Gender

 Female

Reference

Reference

 Male

1.12

1.01–1.24

0.97

0.87–1.09

SAPS3 score

 Box 1 (per point)^a

1.09

1.08–1.10

1.06

1.05–1.07

 Box 2 (per point)

1.05

1.04–1.06

1.03

1.02–1.04

 Box 3 (per point)

1.07

1.06–1.07

1.06

1.06–1.07

Time and day of discharge

 Daytime

Reference

Reference

 Night-time

1.21

1.06–1.38

1.20

1.04–1.40

 Weekday

Reference

Reference

 Weekend

0.92

0.82–1.04

0.98

0.86–1.11

 ICU length of stay (per hour)

1.00

1.00–1.00

1.00

1.00–1.00

Principal disease group^b

Central nervous system injury

Reference

Reference

 COPD^c

1.42

0.85–2.38

1.09

0.65–1.85

 Cardiac arrest

2.77

2.18–3.51

1.56

1.20–2.01

 Acute lung injury

1.43

1.21–1.69

1.15

0.98–1.35

 Sepsis

1.27

1.04–1.55

0.90

0.74–1.09

 Multi-trauma

0.34

0.24–0.47

0.72

0.51–1.02

 Other diagnoses

0.71

0.62–0.82

0.70

0.60–0.83