Table 4. Decision statistics for the change of VE/VCO2 and PETCO2 cut-off values and HVS.
| VE/VCO2 ratio | ||||||
| Δ (peak-rest) | sensitivity | specificity | +LR | -LR | PPV | NPV |
| +5 | 31 (15–51) | 97 (82–100) | 9 (1.2–67) | 0.7 (0.6–0.9) | 90 (55–99) | 58 (52–64) |
| 0 | 52 (33–71) | 83 (64–94) | 3 (1.3–7.2) | 0.6 (0.4–0.9) | 75 (56–88) | 63 (53–72) |
| -5 | 83 (64–94) | 59 (39–76) | 2 (1.3–3.2) | 0.3 (0.1–0.7) | 67 (56–76) | 77 (59–89) |
| -10 | 97 (82–100) | 34 (18–54) | 1.5 (1.1–1.9) | 0.1 (0.01–0.73) | 60 (53–66) | 91 (58–99) |
| PETCO2 (mmHg) | ||||||
| Δ (peak-rest) | sensitivity | specificity | +LR | -LR | PPV | NPV |
| -5 | 21 (8–40) | 100 (88–100) | - | 0.8 (0.7–1) | 100 | 56 (51–60) |
| 0 | 55 (36–74) | 93 (77–99) | 8 (2–31) | 0.5 (0.3–0.7) | 89 (67–97) | 68 (58–76) |
| +5 | 83 (64–94) | 62 (42–79) | 2.2 (1.3–3.6) | 0.3 (0.1–0.7) | 69 (57–78) | 78 (61–89) |
| +10 | 93 (77–99) | 14 (4–32) | 1.1 (0.9–1.3) | 0.5 (0.1–2.5) | 52 (48–56) | 67 (28–91) |
Δ = delta; +LR = positive likelihood ratio; -LR = negative likelihood ratio; NPV = negative predictive value; PETCO2 = partial pressure of end-tidal carbon dioxide; PPV = positive predictive value; VE/VCO2 = ventilatory efficiency