Objective: Iron Deficiency Anemia (IDA) and Beta Thalassemia Minor (BTM) are the most common causes of microcytic hypochromic anemia. In the last four decades many formulas have been proposed to discriminate between two common causes of microcytic hypochromic anemia. An ideal discrimination index should have a high sensitivity and specificity and should be easy to calculate. The distinction between IDA and BTM is important in many respects. In our study, the performance of twelve indices were tested to distinguish IDA from BTM, two common causes of microcytic anemia.

Materials and methods: There were two groups which were evaluated as IDA and BTM, we examined the diagnostic accuracy of five red cell parameters [red blood cell (RBC), mean corpuscular volume (MCV), hemoglobin (Hb) ,mean corpuscular hemoglobin (MCH), red blood cell distribution width (RDW)] and we calculated twelve indices [Menzier Index (MI), Green and King (GK), Red Blood Cell Distribution Width Index (RDWI), England & Fraser (EF), RBC, Sirdah Index (SI), Ricarca Index (R), Srivastava (S), Shine & Lal (SL), Ehsani (E), Red Cell Distribution Width (RDW), 11T].

Results: Among the twelve discrimination indices, 11T index was the most efficient in differentiating IDA from BTM. 11T index had the highest Youdens index (69,8%) and accuracy (81,2%).

Conclusion: 11T index was the most effective in discriminating IDA from BTM. RBC, GK, SI and RDWI could be used as a screening tool rather than discrimination indices.