Table 1 Baseline characteristics and outcomes of the study patients
Characteristics | All patients | Development cohort (2005 to 2008) | Validation cohort (2009) | P value | |||
|---|---|---|---|---|---|---|---|
| Â | n= 390,226 (100%) | n= 307,896 (78.9%) | n= 82,330 (21.1%) | Â | |||
Age, years, mean ± SD | 74.8 | ±14.7 | 74.5 | ±14.7 | 75.6 | ±14.5 | <0.0001 |
Male, n (%) | 225,152 | (57.7%) | 178,165 | (57.9%) | 46,987 | (57.1%) | <0.0001 |
Witnessed arrest, n (%) | 149,701 | (38.4%) | 117,986 | (38.3%) | 31,715 | (38.5%) | 0.291 |
Arrest witnessed by EMS personnel, n (%) | 18,581 | (4.8%) | 14,321 | (4.7%) | 4,260 | (5.2%) | <0.0001 |
Bystander CPR, n (%) | 165,412 | (42.4%) | 123,980 | (40.3%) | 41,432 | (50.3%) | <0.0001 |
Presumed cardiac etiology, n (%) | 276,182 | (70.8%) | 216,241 | (70.2%) | 59,941 | (72.8%) | <0.0001 |
Shockable initial rhythm, n (%) | 36,594 | (9.4%) | 28,745 | (9.3%) | 7,849 | (9.5%) | 0.084 |
Prehospital AED administration (actual shock delivery) | 49,556 | (12.7%) | 39,145 | (12.7%) | 10,411 | (12.7%) | 0.601 |
Call-response time interval, minutes, mean ± SD | 7.24 | ±3.73 | 7.17 | ±3.74 | 7.49 | ±3.66 | <0.0001 |
Call-hospital arrival time interval, minutes, mean ± SD | 29.9 | ±9.9 | 29.7 | ±9.8 | 30.5 | ±10.0 | <0.0001 |
Prehospital ROSC | 20,547 | (5.3%) | 15,361 | (5.0%) | 5,186 | (6.3%) | <0.0001 |
Outcome 1 month after cardiac arrest | Â | Â | Â | Â | Â | Â | Â |
   Survival, n (%) | 16,332 | (4.2%) | 12,514 | (4.1%) | 3,818 | (4.6%) | <0.0001 |
   Favorable neurologic outcome (CPC = 1 to 2), n (%) | 7,768 | (2.0%) | 5,777 | (1.9%) | 1991 | (2.4%) | <0.0001 |