Test characteristics based on optimal cutoff values determined by ROC analysis
| . | Sensitivity (%) . | Specificity (%) . | PPV (%) . | NPV (%) . | ROC area* . |
|---|---|---|---|---|---|
| CHr (no more than 28.0 pg) | 60.7 | 76.0 | 58.6 | 77.6 | 0.642 ± 0.15 |
| CHr† | 73.9 | 73.3 | 58.6 | 84.6 | 0.735 ± 0.14 |
| Ferritin (no more than 50 mg/L) | 42.3 | 93.6 | 78.6 | 74.6 | 0.660 ± 0.14 |
| Ferritin† | 52.4 | 92.9 | 78.6 | 79.6 | 0.690 ± 0.15 |
| Tf sat (no more than 13%) | 62.5 | 73.8 | 57.7 | 77.5 | 0.660 ± 0.15 |
| Tf sat† | 65.0 | 70.3 | 54.2 | 78.8 | 0.637 ± 0.16 |
| MCV (no more than 81 fL) | 25.9 | 94.0 | 70.0 | 70.1 | 0.505 ± 0.15 |
| MCV† | 31.8 | 93.3 | 70.0 | 73.7 | 0.570 ± 0.15 |
| . | Sensitivity (%) . | Specificity (%) . | PPV (%) . | NPV (%) . | ROC area* . |
|---|---|---|---|---|---|
| CHr (no more than 28.0 pg) | 60.7 | 76.0 | 58.6 | 77.6 | 0.642 ± 0.15 |
| CHr† | 73.9 | 73.3 | 58.6 | 84.6 | 0.735 ± 0.14 |
| Ferritin (no more than 50 mg/L) | 42.3 | 93.6 | 78.6 | 74.6 | 0.660 ± 0.14 |
| Ferritin† | 52.4 | 92.9 | 78.6 | 79.6 | 0.690 ± 0.15 |
| Tf sat (no more than 13%) | 62.5 | 73.8 | 57.7 | 77.5 | 0.660 ± 0.15 |
| Tf sat† | 65.0 | 70.3 | 54.2 | 78.8 | 0.637 ± 0.16 |
| MCV (no more than 81 fL) | 25.9 | 94.0 | 70.0 | 70.1 | 0.505 ± 0.15 |
| MCV† | 31.8 | 93.3 | 70.0 | 73.7 | 0.570 ± 0.15 |
PPV, positive predictive value; NPV, negative predictive value; ROC, receiver operator curve; CHr, reticulocyte hemoglobin content; Tf sat, transferrin saturation; MCV, mean cellular volume.
The ± 95% confidence interval was calculated by using the Wilcoxon statistic according to Hanley and McNeil.13 14
Values determined after excluding patients with MCV of at least 100 fL.