Better differential diagnosis of iron deficiencyanemia from beta-thalassemia trait

Iron deficiency anemia (IDA) and ß- Thalassemia Trait (ß-TT) are the most common forms of microcytic anemia. This study was conducted to compare the validity of these discrimination indices in differentiating ß- Thalassemia Trait (β-TT) from IDA by calculating their sensitivity, specificity and Youden's index.

Totally 323 subjects (173 children and 150 adult) with microcytic anemia were involved in this study. We calculated 10 discrimination indices in all patients with IDA and β-TT. We divided the patients into two different groups as younger and older than 10 years.

None of indices showed sensitivity and specificity of 100% in the patients older than 11 years, but only Shine and Lal Index showed sensitivity close to 90% and specificity of 100% in the patients younger than 10 years. The most accurate discriminative index for patients younger than 10 years was Shine & Lal and in case of patients older than 11 years it was RDWI. Youden's index for Shine & Lal & RBC Count and for RDWI & RBC Count indices has most diagnostic value for younger and older than 10 years, respectively.

None of the indices was completely sensitive and specific in differentiation between β-TT and IDA. MCHD mean and median were very close to normal values for both IDA and β-TT patients, but in case of MHDL we have found mean and median were significantly higher than normal values in β-TT and lower than those in IDA patients. In our study, Youden's index of RBC and S & L were the highest and the most reliable discrimination indices in differentiating β-TT from IDA in the patients younger than 10 years and for patients older than 11 years, the most reliable discrimination indices were RBC and RDWI.