To explore the application value of RDW, MCV and MCH in distinguishing patients of iron deficiency anemia (IDA) and thalassemia carriers.

The results of 7130 cases of thalassemia gene detection were retrospectively analyzed, and the data of RDW, MCV and MCH of α-TT silent carrier, α-TT trait, HbH disease, β-thalassemia minor, β-thalassemia intermediate, β-thalassemia major, iron deficiency anemia and healthy control groups were compared. Taking α-TT silent carrier, α-TT trait and β-thalassemia minor as the case group respectively, and IDA as the control group, the ROC curves of single indexes of RDW, MCV, MCH and the combination of multiple indexes (RDW+MCV, MCV+MCH, RDW+MCV+MCH) were evaluated, respectively.

Compared with the healthy control group, the results of MCV, MCH and RDW between the three phenotypes of α-thalassemia, three phenotypes of β-thalassemia and IDA were significantly different (P＜0.05). The analysis of ROC curve showed that the AUC of RDW in the identification of α-TT silent carrier and IDA, α-TT trait and IDA, and β-thalassaemia minor and IDA were 0.926, 0.792 and 0.730, and the cut-off values were 0.155, 0.165 and 0.175, respectively. The AUC of MCV in these three groups were 0.830, 0.705 and 0.817, and the cut-off values were 77.75, 72.45 and 66.25, respectively. The AUC of MCH were 0.881, 0.529 and 0.608, and the cut-off values were 24.85, 22.35 and 21.15, respectively. Combining these three indexes, the corresponding AUC were 0.930, 0.944 and 0.969 respectively.

The discriminative value of RDW is higher than that of MCV and MCH. The combined screening of RDW, MCV, and MCH is more effective in distinguishing IDA patients and thalassemia carriers than a single indicator or a combination of the two.