Table 4.

Characteristics of out-of-hospital cardiac arrest (OHCA) patients who received biphasic defibrillation treatment before hospital arrival according to the number of defibrillations

Variable	≤2 times ( n = 13,565)	≥3 times ( n = 7,286)	P -value
(OHCA patients)
Age (yr) (mean ± standard deviation [SD])	66.19 ± 15.32	64.09 ± 15.07	<.0001
Sex (male), no. (%)	10430 (76.89)	5938 (81.50)	<.0001
Origin of OHCA (cardiac origin), no. (%)	11863 (87.45)	6735 (92.44)	<.0001
Relationship between bystander and patient (family member), no. (%)	6997 (51.58)	4197 (57.60)	<.0001
(CPR initiated by bystander)
Chest compressions (yes), no. (%)	6167 (45.46)	3514 (48.23)	<.0001
Rescue breathing (yes), no. (%)	1446 (10.66)	782 (10.73)	.8705
(Life support by EMS personnel)
Emergency life-saving technician in ambulance (yes), no. (%)	13169 (97.08)	7115 (97.65)	.0154
Advanced life support by MD (yes), no. (%)	1628 (12.00)	1020 (14.00)	<.0001
Time from call to arrival at scene (min) (mean ± SD)	7.05 ± 3.24	7.17 ± 3.27	.0159
Time from call to arrival at hospital (min) (mean ± SD)	32.96 ± 15.88	35.02 ± 14.67	<.0001
Use of ALS devices (laryngeal mask/an adjunct airway/ tracheal tubes), no. (%)	4946 (36.46)	3494 (47.95)	<.0001
Epinephrine use (yes), no. (%)	2207 (16.27)	2437 (33.45)	<.0001
Time from the first defibrillation to the first ROSC before hospital arrival (min) (mean ± SD)	6.27 ± 9.63	11.91 ± 8.09	<.0001
Number of defibrillations by EMS personnel (mean ± SD)	1.38 (0.49)	4.18 (1.55)	<.0001
Proportions of the number of defibrillations (%)			<.0001
1	8403 (61.95)	0 (0.00)
≥2	5162 (38.05)	7286 (100.00)
Frequency of patients who took ≤1 min. from the first defibrillation to the first ROSC before hospital arrival (%)	2393 (17.64)	350 (4.81)	<.0001
(Endpoint)
1-month survival after cardiac arrest (yes), no. (%)	4677 (34.48)	1803 (24.75)	<.0001
ROSC (yes), no. (%)	5188 (38.25)	1688 (23.17)	<.0001