Table 4. Receiver operating characteristic (ROC) curve analysis of different discriminant formulas according to cut-off values in the literature in the iron deficiency anemia (IDA), β-thalassemia trait (β-TT), and α-thalassemia trait (α-TT) groups.
| DF | Groups | AUC (95% CI) | Proposed cut-off | Sensitivity (%) | Specificity (%) | +LR | −LR | Youden index (%) |
|---|---|---|---|---|---|---|---|---|
| E&F | IDA/α-TT | 0.651 (0.579–0.723) | 0 | 6.1 | 99.4 | 15.45 | 0.91 | 5.5 |
| IDA/β-TT | 0.677 (0.593–0.761) | 0 | 6.2 | 99.4 | 10.63 | 0.94 | 5.6 | |
| MI | IDA/α-TT | 0.650 (0.583–0.718) | 13 | 10.6 | 92.4 | 1.39 | 0.97 | 3.0 |
| IDA/β-TT | 0.710 (0.634–0.785) | 13 | 16.7 | 93.5 | 2.58 | 0.89 | 10.2 | |
| Sriv | IDA/α-TT | 0.660 (0.592–0.727) | 3.8 | 6.1 | 97.7 | 2.58 | 0.96 | 3.8 |
| IDA/β-TT | 0.718 (0.644–0.793) | 3.8 | 8.3 | 97.6 | 3.54 | 0.94 | 8.0 | |
| S&L | IDA/α-TT | 0.604 (0.537–0.672) | 1,530 | 93.9 | 20.6 | 1.13 | 0.36 | 14.5 |
| IDA/β-TT | 0.717 (0.652–0.783) | 1,530 | 97.9 | 20.6 | 0.22 | 0.11 | 18.5 | |
| RDWI | IDA/α-TT | 0.615 (0.543–0.687) | 220 | 40.9 | 72.9 | 0.51 | 0.81 | 13.8 |
| IDA/β-TT | 0.637 (0.559–0.714) | 220 | 43.7 | 72.6 | 1.52 | 0.79 | 16.3 | |
| RI | IDA/α-TT | 0.626 (0.544–0.708) | 4.4 | 87.9 | 8.5 | 0.99 | 1.08 | 26.2 |
| IDA/β-TT | 0.559 (0.476–0.641) | 4.4 | 97.9 | 9.7 | 1.10 | 0.20 | 7.6 | |
| G&K | IDA/α-TT | 0.611 (0.537–0.685) | 65 | 19.7 | 86.2 | 1.29 | 0.95 | 5.9 |
| IDA/β-TT | 0.617 (0.536–0.697) | 65 | 18.8 | 86.8 | 1.42 | 0.94 | 5.0 | |
| Logit-P1 | IDA/α-TT | 0.606 (0.521–0.690) | 1.26 | 24.2 | 90.6 | 2.58 | 0.84 | 14.8 |
| IDA/β-TT | 0.782 (0.707–0.858) | 1.26 | 41.7 | 90.0 | 4.17 | 0.65 | 31.7 | |
| MHA 1 | IDA/α-TT | 0.868 (0.822–0.914) | 0.61 | 90.9 | 68.6 | 2.89 | 0.13 | 59.4 |
| IDA/β-TT | 0.806 (0.738–0.874) | 0.69 | 83.33 | 65.59 | 2.42 | 0.25 | 48.92 | |
| MHA 2 | IDA/α-TT | 0.772 (0.712–0.833) | 0.85 | 78.8 | 64.1 | 2.20 | 0.33 | 42.9 |
| IDA/β-TT | 0.878 (0.824–0.932) | 0.37 | 72.9 | 89.7 | 7.08 | 0.30 | 62.6 |
DF, discriminant formulas; AUC, area under the curve; Sensitivity, true positive/(true positive + false negative); Specificity, true negative/(true negative + false positive); E&F, England and Fraser Index; G&K, Green and King Index; MI, Mentzer Index; RDWI, red blood cell distribution width index; S&L, Shine and Lal Index; Srivastava, Srivastava Index.