Ratio of hemoglobin to mean corpuscular volume: A new index for discriminating between iron deficiency anemia and thalassemia trait.

BACKGROUND: Iron deficiency anemia (IDA) and thalassemia trait (TT) are the most common microcytic and hypochromic anemias. Differentiation between mild TT and early IDA is still a clinical challenge.

AIM: To develop and validate a new index for discriminating between IDA and TT.

METHODS: Blood count data from 126 patients, consisting of 43 TT patients and 83 IDA patients, was retrospectively analyzed to develop a new index formula. This formula was further validated in another 61 patients, consisting of 48 TT patients and 13 IDA patients.

RESULTS: The new index is the ratio of hemoglobin to mean corpuscular volume. Its sensitivity, specificity, accuracy, Youden's Index, area under the receiver operating characteristic curve, and Kappa coefficient in discriminating between IDA and TT were 93.5%, 78.4%, 83.3%, 0.72, 0.97, and 0.65, respectively.

CONCLUSION: This new index has good diagnostic performance in discriminating between mild TT and early IDA. It requires only two results of complete blood count, which can be a very desirable feature in under-resourced scenarios.