Table 8 Accuracy of Δ residual volume (RV) and Δ total lung capacity (TLC) in prediction of response based on forced expiratory volume in first second (FEV1)
Δ RV | Δ TLC | |
|---|---|---|
Sensitivity | 70% | 90% |
Specificity | 60% | 45% |
Positive predictive value | 69.5% | 90% |
Negative predictive value | 94% | 45% |
Accuracy | 61% | 50% |
Cutoff point | > 20% | > 12% |
Area under curve | 0.60 | 0.60 |