Sirdah Index (Thalassemia vs Iron Deficiency)
Sirdah index: MCV − RBC − (3 × Hb); a value below ~27 favors beta-thalassemia trait over iron-deficiency anemia.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- MCV
- 65 fL
- RBC count
- 5.5 ×10¹²/L
- Hemoglobin
- 12.5 g/dL
Result: Sirdah index 22 — favors beta-thalassemia trait (cutoff 27).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- < 27
- Favors beta-thalassemia trait.
- > 27
- Favors iron-deficiency anemia. Index = MCV - RBC - (3 x Hb). A screen, not a diagnosis — confirm with electrophoresis and iron studies.
What you enter
- MCV
- RBC count
- Hemoglobin
How this is calculated
Sirdah M, Tarazi I, Al Najjar E, Al Haddad R. Evaluation of the diagnostic reliability of different RBC indices and formulas in the differentiation of the beta-thalassaemia minor from iron deficiency in Palestinian population. Int J Lab Hematol. 2008;30(4):324-330. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.