Table 1. Discriminant formulas for distinguishing thalassemia trait (TT) from iron deficiency anemia (IDA) in patients with microcytic red blood cells (RBCs).
| Abbr. | DF (reference) | Calculation | Cut-off thala. |
|---|---|---|---|
| E&F | England & Fraser (10) | MCV − (5 × Hb) − RBC −3.4 | <0 |
| MI | Mentzler (11) | MCV/RBC | <13 |
| Sriv | Srivastava (12) | MCH/RBC | <3.8 |
| S&L | Shine & Lal (13) | MCV2 × MCH | <1530 |
| RDWI | RDW index (14) | MCV × RDW/RBC | <220 |
| RI | Ricerca (15) | RDW/RBC | <4.4 |
| G&K | Green & King (16) | MCV2 × RDW/l00 Hb | <65 |
| Logit-P1 | Logit-P1 (31) | −10.14+1.64× RBC + 0.85× Ret% + 0.07× IRF | <0.84 |
Abbr., abbreviation; DF, discriminant formula; thala., thalassemia.