Table 1 Calculations for the sample size
VFDs | Probability of getting off ventilation alive | Probability of death | Probability of receiving ventilation | Expected mortality | ||
|---|---|---|---|---|---|---|
Mean | SD | pa | pd | po | 60-day mortality | |
Control group | 9.0 | 10.7 | 0.0481 | 0.0500 | 0.9019 | 0.4814 |
Experimental group | 12.0 | 10.8 | 0.0641 | 0.0345 | 0.9014 | 0.3308 |
Difference | 3.0 | 0.0160 | -0.0155 | -0.0005 | -0.1506 |