Table 3 Summary statistics for the three variables used to predict extubation success.
| Variable | PPV (%) | NPV (%) | Sens (%) | Spec (%) | LR+ | LR− |
|---|---|---|---|---|---|---|
| SBT | 93 | 89 | 97 | 73 | 3.6 | 0.04 |
| V̇e (ET CPAP) >220 ml/kg/min | 87 | 50 | 85 | 45 | 1.9 | 0.27 |
| V̇e ratio ⩾0.8 | 87 | 55 | 87 | 54 | 1.9 | 0.24 |
PPV, positive predictive value; NPV, negative predictive value; Sens, sensitivity; Spec, specificity; LR+, positive likelihood ratio; LR−, negative likelihood ratio; SBT, spontaneous breathing test; V̇e, minute ventilation; ET CPAP, endotracheal continuous positive airway pressure.