RESUMO
Distinguishing two common hypochromic microcytic anemias [i.e. iron deficiency anemia and thalassemia] needs expensive laboratory test not readily available everywhere. For better discrimination of minor thalassemia from iron deficiency anemia some formulas are available, of them four formulas of England, Mentzer, Shine and MDHL are compared here and superiority of MDHL proved. The four indices were calculated for 108 proved thalassemia minor patients and 199 iron deficients [total 307cases]. The best cut-off point for each index was selected by received operator characteristics analysis the highest sensitivity possible to separate thalassemics form iron deficient. Sensitivity, specificity and efficacy of indices were compared. Mentzer's index [sensitivity: 93.5, specificity: 82.0, efficacy: 86.64] and MDHL [sensitivity: 95.4, specificity: 80.9, efficacy: 85.99] had better results. Interpretation: it seems that these indices can be used to screen microcytic anemic patients, reserving haemoglobin electrophoresis, genetic studies, serum iron and ferritin measurement for selected patients, lowering public health costs