IRON-DEFICIENCY ANEMIA AND THALASSEMIA TRAIT DIFFERENTIATED BY SIMPLEHEMATOLOGICAL TESTS AND SERUM IRON CONCENTRATIONS

The diagnostic value of common hematology tests in differentiating bet ween thalassemia trait and iron-deficiency anemia (IDA) was assessed. Serum iron concentration was included in a second stage of the diagnos tic model and its predictive contribution was determined. After applyi ng discriminant analysis to the data, minimization of Wilks's lambda ( A) criterion was used to select the best predictive variables. A train ing sample of 754 subjects previously classified as either IDA (428) o r thalassemia trait (326) was used to determine the classification rul e. When serum iron concentrations were included, the model showed a hi gher predictive capacity than that constructed from hematological vari ables only (D = 2.342 RBC - 0.079 Hb + 3.627 log[Fe] - 6.459, where D = discriminant score). The sensitivity, specificity, and diagnostic ef ficiency associated with this model, as assessed on a control sample o f 256 patients (137 thalassemia and 119 IDA), were 94.2%, 91.6%, and 9 3.0%, respectively. This model, when compared with those of other auth ors, has the highest diagnostic efficiency.