Table 3.
ROC curves analysis and kappa statistic analysis
| Cut point | ROC Points
|
Kappa statistic (95% CI) | ||
|---|---|---|---|---|
| Sensitivity (%) | Specificity (%) | Youden index (bootstrap 95% CI) | ||
| ≥0 | 100.00 | 0.00 | ||
| ≥1 | 100.00 | 0.65 | 0.01 (0.00–0.01) | 0.00 (0.00–0.01) |
| ≥2 | 100.00 | 1.47 | 0.01 (0.01–0.02) | 0.01 (0.01–0.02) |
| ≥3 | 100.00 | 2.40 | 0.02 (0.01–0.03) | 0.02 (0.01–0.02) |
| ≥4 | 100.00 | 3.96 | 0.04 (0.03–0.05) | 0.03 (0.02–0.04) |
| ≥5 | 100.00 | 5.53 | 0.06 (0.04–0.07) | 0.04 (0.03–0.05) |
| ≥6 | 100.00 | 7.00 | 0.07 (0.06–0.08) | 0.05 (0.04–0.06) |
| ≥7 | 99.83 | 9.12 | 0.09 (0.07–0.11) | 0.06 (0.05–0.07) |
| ≥8 | 99.83 | 10.97 | 0.11 (0.09–0.13) | 0.08 (0.06–0.09) |
| ≥9 | 99.83 | 15.21 | 0.15 (0.13–0.17) | 0.11 (0.09–0.13) |
| ≥10 | 99.48 | 18.25 | 0.18 (0.15–0.20) | 0.13 (0.11–0.15) |
| ≥11 | 98.95 | 22.95 | 0.22 (0.19–0.24) | 0.16 (0.14–0.19) |
| ≥12 | 98.61 | 27.93 | 0.27 (0.24–0.29) | 0.20 (0.18–0.23) |
| ≥13 | 97.91 | 32.26 | 0.30 (0.27–0.33) | 0.23 (0.21–0.26) |
| ≥14 | 96.86 | 35.67 | 0.33 (0.30–0.36) | 0.25 (0.22–0.29) |
| ≥15 | 95.99 | 39.54 | 0.36 (0.32–0.38) | 0.28 (0.25–0.31) |
| ≥16 | 94.60 | 42.49 | 0.37 (0.34–0.41) | 0.30 (0.27–0.33) |
| ≥17 | 93.38 | 47.28 | 0.41 (0.37–0.44) | 0.33 (0.30–0.39) |
| ≥18 | 90.07 | 50.14 | 0.40 (0.36–0.44) | 0.34 (0.30–0.37) |
| ≥19 | 88.15 | 54.84 | 0.43 (0.39–0.47) | 0.37 (0.33–0.40) |
| ≥20 | 86.06 | 58.53 | 0.45 (0.41–0.49) | 0.39 (0.35–0.43) |
| ≥21 | 81.71 | 62.49 | 0.44 (0.40–0.48) | 0.39 (0.35–0.43) |
| ≥22 | 78.40 | 67.56 | 0.46 (0.42–0.50) | 0.42 (0.38–0.46) |
| ≥23 | 73.34 | 71.61 | 0.45 (0.40–0.50) | 0.42 (0.42–0.38) |
| ≥24 | 70.38 | 76.13 | 0.47 (0.42–0.51) | 0.45 (0.40–0.49) |
| ≥25 | 64.46 | 80.00 | 0.44 (0.40–0.49) | 0.44 (0.40–0.49) |
| ≥26 | 59.93 | 84.06 | 0.44 (0.40–0.49) | 0.45 (0.40–0.50) |
| ≥27 | 53.48 | 87.83 | 0.41 (0.36–0.46) | 0.44 (0.40–0.48) |
| ≥28 | 46.86 | 91.34 | 0.38 (0.34–0.42) | 0.42 (0.37–0.46) |
| ≥29 | 39.20 | 94.01 | 0.33 (0.29–0.38) | 0.38 (0.33–0.42) |
| ≥30 | 33.97 | 96.13 | 0.30 (0.26–0.34) | 0.35 (0.30–0.39) |
| ≥31 | 29.27 | 97.70 | 0.27 (0.23–0.30) | 0.32 (0.28–0.36) |
| ≥32 | 25.09 | 98.43 | 0.24 (0.20–0.27) | 0.28 (0.24–0.32) |
| ≥33 | 19.34 | 99.26 | 0.19 (0.15–0.22) | 0.23 (0.19–0.27) |
| ≥34 | 15.51 | 99.63 | 0.15 (0.12–0.18) | 0.19 (0.15–0.22) |
| ≥35 | 11.32 | 99.83 | 0.11 (0.09–0.14) | 0.14 (0.11–0.17) |
| ≥36 | 7.49 | 99.83 | 0.07 (0.05–0.09) | 0.09 (0.07–0.12) |
| ≥37 | 5.57 | 99.83 | 0.05 (0.03–0.07) | 0.07 (0.05–0.09) |
| ≥38 | 3.83 | 99.91 | 0.04 (0.02–0.05) | 0.05 (0.02–0.07) |
| ≥39 | 2.79 | 99.91 | 0.02 (0.01–0.04) | 0.03 (0.02–0.05) |
| ≥40 | 1.39 | 99.91 | 0.01 (0.00–0.02) | 0.02 (0.00–0.03) |
| ≥41 | 0.00 | 100.00 | ||
Notes: ROC: 1,659 patients; Area under the curve (standard error) =0.82 (0.01); 95% CI 0.80, 0.84. Bold font indicates where the Youden index and kappa statistic are maximized.
Abbreviations: CI, confidence interval; ROC, receiver operating characteristic.