Table 2. Characteristics of study population by scene time interval.
| Characteristics | Scene time interval | P value | ||
|---|---|---|---|---|
| 1–5 min (n = 12,652) | > 5 min (n = 45,170) | |||
| Age, yr, mean (SD) | 69.9 (15.0) | 70.0 (15.2) | 0.319 | |
| Men, No. (%) | 7,784 (61.5) | 28,460 (63.0) | 0.002 | |
| Past medical history, No. (%) | ||||
| Diabetes mellitus | 2,459 (19.4) | 9,646 (21.4) | < 0.001 | |
| Hypertension | 3,852 (30.4) | 14,385 (31.8) | 0.003 | |
| Heart disease | 1,690 (13.4) | 6,251 (13.8) | 0.169 | |
| Stroke | 1,005 (7.9) | 4,184 (9.3) | < 0.001 | |
| Medical aid, No. (%) | 1,137 (9.0) | 3,900 (8.6) | 0.220 | |
| Community urbanization, No. (%) | < 0.001 | |||
| Metropolitan | 5,118 (40.5) | 19,736 (43.7) | ||
| Circumstance of arrest, No. (%) | ||||
| Public location | 3,082 (24.4) | 6,362 (14.1) | < 0.001 | |
| Witnessed | 5,318 (42.0) | 19,224 (42.6) | 0.294 | |
| Bystander CPR | 5,118 (40.5) | 22,088 (48.9) | < 0.001 | |
| Initial ECG, No. (%) | 0.023 | |||
| Asystole | 9,888 (78.2) | 34,810 (77.1) | ||
| PEA | 1,277 (10.1) | 4,685 (10.4) | ||
| Shockable rhythm | 1,487 (11.8) | 5,675 (12.6) | ||
| Prehospital management, No. (%) | ||||
| Defibrillation | 2,225 (17.6) | 8,998 (19.9) | < 0.001 | |
| Advanced airway management | 1,054 (8.3) | 7,085 (15.7) | < 0.001 | |
| Mechanical CPR | 48 (0.4) | 201 (0.4) | 0.358 | |
| Elapsed time, median (IQR), min | ||||
| EMS response time | 7.0 (5.0–10.0) | 7.0 (5.0–10.0) | 0.656 | |
| Scene time | 4.0 (3.0–5.0) | 10.0 (8.0–13.0) | < 0.001 | |
| Transport time | 7.0 (5.0–12.0) | 6.0 (4.0–10.0) | < 0.001 | |
| Volume of center, No. (%) | < 0.001 | |||
| High volume (≥ 40 cases) | 8,884 (70.2) | 32,707 (72.4) | ||
| Post resuscitation care, No. (%) | ||||
| Reperfusion | 200 (1.6) | 445 (1.0) | < 0.001 | |
| Hypothermia | 357 (2.8) | 858 (1.9) | < 0.001 | |
| ECMO | 95 (0.8) | 317 (0.7) | 0.603 | |
| Outcome, No. (%) | ||||
| Survival to discharge | 516 (4.1) | 967 (2.1) | < 0.001 | |
| Good neurologic recovery | 158 (1.2) | 240 (0.5) | < 0.001 | |
SD = standard deviation, ECG = electrocardiogram, PEA = Pulseless electrical activity, CPR = cardiopulmonary resuscitation, IQR = interquartile range, EMS = emergency medical service, ECMO = extracorporeal membrane oxygenation.