Introduction: Thalassemia traits and iron deficiency anemia are the most common types of hypochromic microcytic anemia with similar clinical and laboratory features. It is vital to establish a new screening model based on HbA2 levels and red cell indices for the differentiation of TT from IDA in hypochromic microcytic anemia cases.
Method: The data comprised of the red blood cell indices and HbA2 prenatal diagnostic test results of 810 individuals who were identified to conform to the following criteria: MCV < 80 fl or MCH < 26 pg. We launched a new model consisting mainly of significative red cell indices and HbA2 levels, as well as proposing cutoff values by using decision trees and logistic regression analyses. Next, we evaluated our new method by comparing the sensitivity, specificity, positive, and negative predictive values with those of the previous formulas.
Results: We put forward a new model and compared it with 5 efficient formulas. The new model exhibited the highest accuracy (0.918), with its sensitivity and specificity calculated as 0.917 and 0.921, respectively. Our new model's Youden index was 0.838, which is higher than the other formulas' Youden indices.
Conclusions: The new screening model, based on HbA2 levels and red cell indices, is suitable for the screening of thalassemia patients in the hypochromic microcytic anemia group and has the best efficiency in distinguishing TT and IDA.
Keywords: hypochromic microcytic anemia; iron deficiency anemia; α- and β-thalassemia trait.
© 2020 John Wiley & Sons Ltd.