Table 3. Diagnostic statistics for assessing accuracies for the indices at the mean values.
ROX: Respiratory rate-oxygenation index, mROX: modified Respiratory rate-oxygenation index. Note- *mark indicates that the values were specific for high-flow nasal cannula failure prevalence of 48.15%, as found in our study.
| Statistic | Value (95% Confidence Interval) | |||
| ROX at baseline [mean 4.78] | mROX at baseline [mean 3.98] | ROX at 6 hours [mean 4.5] | mROX at 6 hours [mean 4.05] | |
| Sensitivity (%) | 63.64 (30.79 - 89.07) | 75.00 (42.81 - 94.51) | 72.73 (39.03 - 93.98) | 87.50 (47.35 - 99.68) |
| Specificity (%) | 56.25 (29.88 - 80.25) | 66.67 (38.38 - 88.18) | 62.50 (35.43 - 84.80) | 63.16 (38.36 - 83.71) |
| Positive Likelihood Ratio | 1.45 (0.71 - 2.97) | 2.25 (1.02 - 4.94) | 1.94 (0.94 - 4.02) | 2.37 (1.25 - 4.52) |
| Negative Likelihood Ratio | 0.65 (0.26 - 1.58) | 0.38 (0.13 - 1.06) | 0.44 (0.15 - 1.23) | 0.20 (0.03 - 1.28) |
| Positive Predictive Value (*) | 57.46 (39.84 - 73.37) | 67.63 (48.75 - 82.1) | 64.30 (46.49 - 78.87) | 68.80 (53.66 - 80.77) |
| Negative Predictive Value (*) | 62.49 (40.54 - 80.27) | 74.17 (50.29 - 89.07) | 71.16 (46.66 - 87.44) | 84.47 (45.73 - 97.23) |
| Accuracy (*) | 59.81 (39.32 - 78.06) | 70.68 (50.14 - 86.47) | 67.42 (46.80 - 84.06) | 74.88 (54.58 - 89.44) |
| Sensitivity + Specificity | 119.85% (1.198) | 141.6% (1.416) | 135.2% (1.352) | 150.66% (1.566) |