Table 1 Patient characteristics.

From: Prehospital predicting factors using a decision tree model for patients with witnessed out-of-hospital cardiac arrest and an initial shockable rhythm

Variable

All patient (n = 86,495)

Development cohort (n = 77,845)

Validation cohort (n = 8650)

Standardized difference

Age (years)

65.7 ± 15.3

65.7 ± 15.3

65.5 ± 15.5

− 0.01

Male

68,027 (78.7%)

61,515 (78.6%)

6876 (79.5%)

− 0.008

Treatment by citizen

43,412 (50.2%)

39,124 (50.3%)

4288 (49.6%)

0.005

Chest compression by citizen

42,673 (49.3%)

38,460 (49.4%)

4213 (48.7%)

0.005

Rescue breathing by citizen

9976 (11.5%)

8968 (11.5%)

1008 (11.7%)

− 0.002

AED by citizen

3387 (3.9%)

3039 (3.9%)

348 (4.0%)

− 0.002

EMS witness

10,215 (11.8%)

9220 (11.8%)

995 (11.5%)

0.003

Biphasic defibrillation

77,724 (89.9%)

69,965 (89.9%)

7759 (89.7%)

0.002

Defibrillation times

2.5 ± 1.8

2.5 ± 1.8

2.5 ± 1.8

0.000

Adrenaline

19,772 (22.9%)

17,731 (22.8%)

2041 (23.6%)

− 0.007

Prehospital ROSC

28,695 (33.2%)

25,849 (33.2%)

2846 (32.9%)

0.002

Collapse-CPR time

9.4 ± 6.2

9.4 ± 6.2

9.4 ± 6.2

0.000

Collapse-first defibrillation time

11.4 ± 6.8

11.4 ± 6.8

11.4 ± 6.8

0.000

Collapse-hospital arrival time

33.0 ± 14.5

33.0 ± 14.5

33.0 ± 14.7

0.000

Daytime admission

54,248 (62.7%)

48,791 (62.7%)

5457 (63.1%)

− 0.003

Weekend admission

30,286 (35.0%)

27,213 (35.0%)

3073 (35.5%)

− 0.004

Survival at 1-month

27,496 (31.8%)

24,761 (31.8%)

2735 (31.6%)

0.002

Neurologically favorable survival at 1-month

19,190 (22.2%)

17,284 (22.2%)

1906 (22.0%)

0.001

  1. Data are presented as number (%) of patients, mean ± standard deviation.
  2. AED, automated external defibrillator; CPC, cerebral performance category; CPR, cardiopulmonary resuscitation; EMS, emergency medical services; ROSC, return of spontaneous circulation.