Table 3 Univariable analysis for the 30-day favourable neurological outcome according to cerebral performance category (CPC) 1 & 2 of all cases (n = 296)

Weekend mission

1.67

(0.90; 3.10)

0.106

Season

 Winter

1.00

(baseline)

 Spring

0.89

(0.38; 2.07)

0.792

 Summer

1.20

(0.54; 2.66)

0.655

 Fall

0.71

(0.27; 1.89)

0.492

Helicopter hoist operation

0.29

(0.04; 2.28)

0.241

Remote location

1.06

(0.49; 2.26)

0.890

Age in years

0.95

(0.90; 1.01)

0.092

Age group

 < 1 years

1.00

(baseline)

 1–6 years

1.33

(0.61; 2.92)

0.474

 7–16 years

0.64

(0.28; 1.47)

0.291

Sex

 Male

1.00

(baseline)

 Female

1.14

(0.63; 2.06)

0.662

Pre-existing co-morbidities

 Cardiovascular

1.15

(0.37; 3.62)

0.806

 Respiratory

0.42

(0.05; 3.34)

0.411

 Premature birth

1.44

(0.15; 14.07)

0.756

 Neurological

1.64

(0.42; 6.40)

0.475

 Syndrome

0.71

(0.08; 6.01)

0.753

 Diabetes

-

Dispatcher-identified cardiac arrest

1.43

(0.79; 2.56)

0.236

Dispatcher-assisted CPR

0.94

(0.41; 2.16)

0.892

Witnessed cardiac arrest

1.79

(1.00; 3.23)

0.051

Bystander CPR

8.52

(2.98; 24.32)

< 0.001

ALS before HEMS arrival

0.74

(0.40; 1.37)

0.339

Ongoing chest compressions at HEMS arrival

0.14

(0.07; 0.27)

< 0.001

Use of mechanical CPR device

-

Resuscitation delay (> 2 min)

0.18

(0.09; 0.36)

< 0.001

Initial rhythm

 Asystole

0.03

(0.01; 0.10)

< 0.001

 Pulseless electrical activity (PEA)

0.49

(0.18; 1.31)

0.154

 Shockable rhythm

1.29

(0.45; 3.65)

0.636

Number of shocks

0.69

(0.34; 1.41)

0.311

Adrenaline

0.06

(0.03; 0.13)

< 0.001

Tracheal tube

0.26

(0.14; 0.48)

< 0.001

Transport under ongoing CPR

0.25

(0.09; 0.71)

0.010

Traumatic aetiology

0.09

(0.03; 0.29)

< 0.001

Non-traumatic aetiology

11.37

(3.45; 37.45)

< 0.001