Table 3. Subgroup Analysis of ETI Effect Among Different Subgroups.
| Variable | No. | Intention-to-treat ETI effect, OR (95% CI) | |||
|---|---|---|---|---|---|
| ROSC | Survival to discharge | CPC score ≤2 | |||
| Sustained | Prehospital | ||||
| Shockable rhythm | |||||
| Yes | 147 | 1.38 (0.69-2.76) | 2.51 (0.88-7.13) | 1.28 (0.57-2.97) | 0.88 (0.34-2.28) |
| No | 789 | 0.93 (0.67-1.30) | 1.42 (0.82-2.47) | 0.76 (0.42-1.37) | 0.50 (0.20-1.29) |
| Public location | |||||
| Yes | 133 | 0.67 (0.33-1.34) | 0.93 (0.35-2.47) | 0.55 (0.23-1.31) | 0.78 (0.26-2.37) |
| No | 803 | 1.18 (0.85-1.64) | 2.13 (1.21-3.74)a | 1.37 (0.77-2.43) | 0.81 (0.37-1.78) |
| Arrest witnessed | |||||
| Yes | 419 | 1.23 (0.83-1.83) | 1.94 (1.12-3.34)a | 1.20 (0.69-2.09) | 0.90 (0.43-1.90) |
| No | 517 | 1.02 (0.63-1.65) | 2.06 (0.65-6.56) | 0.90 (0.37-2.22) | 0.74 (0.21-2.59) |
| Call to airway time | |||||
| <14 | 362 | 1.31 (0.81-2.11) | 2.03 (0.97-4.25) | 1.34 (0.65-2.78) | 1.31 (0.45-3.83) |
| ≥14 | 454 | 1.03 (0.66-1.62) | 1.63 (0.79-3.36) | 0.86 (0.42-1.80) | 0.58 (0.23-1.50) |
| Age, y | |||||
| <77 | 466 | 0.84 (0.57-1.24) | 1.09 (0.59-2.00) | 0.99 (0.57-1.72) | 0.89 (0.44-1.78) |
| ≥77 | 470 | 1.43 (0.91-2.26) | 3.57 (1.53-8.34)a,b | 1.11 (0.46-2.70) | 0.41 (0.08-2.28) |
Abbreviations: CPC, cerebral performance category; ETI, endotracheal intubation; OR, odds ratio; ROSC, return of spontaneous circulation.
a
P < .05.
b
The P value for interaction test is .03.