Table 1.
Baseline characteristics of the study patients a
|
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 |
aAED, automated external defibrillator; CPC, Cerebral Performance Category; CPR, cardiopulmonary resuscitation; EMS, emergency medical services; ROSC, return of spontaneous circulation. Values are reported as either number of patients (%) or medians (interquartile range [1st to 3rd quartiles]).