End-tidal carbon dioxide classification table over a range of cut-off thresholds
| ETCO2, kPa | Sensitivity, % | Specificity, % | Positive predictive value, % | Negative predictive value, % |
|---|---|---|---|---|
| 1 | 0 | 100 | 0 | 65 |
| 2 | 1 | 98 | 25 | 65 |
| 3 | 60 | 89 | 75 | 81 |
| 4 | 87 | 75 | 66 | 92 |
| 4.3 | 99 | 65 | 60 | 99 |
| 5 | 100 | 25 | 42 | 100 |
| 6 | 100 | 9 | 37 | 100 |
ETCO2 = end-tidal carbon dioxide.