Mentzer (Thalassemic) Index
Not yet clinically reviewed
This protocol was migrated from the earlier Pharmapedia and Ward Guide apps for educational use. Follow your hospital's own policies and consult seniors when in doubt.
The Mentzer index is used to differentiate iron deficiency anemia from beta thalassemia. It is calculated from the result of complete blood count (CBC). If the quotient of MCV divided by the RBC count is less than 13, then thalassemia is more likely to occur. If the result is greater than 14, then iron deficiency anemia is more likely to occur.
In iron deficiency, the bone marrow cannot produce as many RBCs and they are small (microcytic), so the RBC count and MCV will both be low, as a result the index will be greater than 13
In thalassemia, the number od RBCs produced is normal but the cells are smaller and more fragile. Therefore, the RBCs count are normal, but the MCV is low, so the index will be less than 13
Mentzer (Thalassemic) Index=(MCV (fl))/(RBCs(millions/μL))