Characteristics | All patients | Development group, 2005 to 2008 | Validation group, 2009 | P- value |
---|---|---|---|---|
 | (N= 495,607, 100%) | (n= 390,577, 78.8%) | (n= 105,030, 21.2%) |  |
Age, years | 76 (64 to 84) | 76 (64 to 84) | 77 (65 to 85) | <0.0001 |
Males | 290,712 (58.7%) | 229,822 (58.8%) | 60,890 (58.0%) | <0.0001 |
Witnessed cardiac arrest | 188,471 (38.0%) | 147,997 (37.9%) | 40,474 (38.5%) | <0.0001 |
Cardiac arrest witnessed by EMS personnel | 22,722 (4.6%) | 17,514 (4.5%) | 5,208 (5.0%) | <0.0001 |
Bystander CPR | 202,827 (40.9%) | 151,712 (38.8%) | 51,115 (48.7%) | <0.0001 |
Presumed cardiac etiology | 276,183 (55.7%) | 216,242 (55.4%) | 59,941 (57.0%) | <0.0001 |
Shockable initial cardiac rhythm | 38,388 (7.75%) | 30,154 (7.7%) | 8,234 (7.8%) | 0.1992 |
Prehospital AED administration | 53,427 (10.8%) | 42,216 (10.8%) | 11,211 (10.7%) | 0.212 |
Call-to-response time, minutes | 9 (7 to 11) | 6 (5 to 9) | 7 (5 to 9) | <0.0001 |
Call-to-hospital arrival time, minutes | 29 (23 to 36) | 29 (23 to 36) | 30 (24 to 37) | <0.0001 |
Prehospital ROSC | 25,254 (5.1%) | 18,835 (4.8%) | 6,419 (6.1%) | <0.0001 |
One-month outcome after cardiac arrest | ||||
Survival | 19,453 (3.93%) | 14,898 (3.81%) | 4,555 (4.34%) | <0.0001 |
Favorable neurological outcome (CPC category 1 or 2) | 8,391 (1.69%) | 6,244 (1.60%) | 2,147 (2.04%) | <0.0001 |