🩸 Sokal Index (Chronic Myeloid Leukemia)
The Sokal index is a classic pre-treatment prognostic score for newly diagnosed chronic-phase chronic myeloid leukemia (CML), derived from age, spleen size, platelet count, and peripheral blasts.
Sokal Index (Chronic Myeloid Leukemia)
Age (years)
Spleen size (below costal margin) (cm)
Platelets (×10⁹/L)
Peripheral blood blasts (%)
When to use
Enter age, spleen size below the costal margin (cm), platelet count, and peripheral blood blast percentage; the tool returns the relative-risk value and risk group.
How it works
Exp[0.0116 × (age − 43.4) + 0.0345 × (spleen − 7.51) + 0.188 × ((platelets/700)² − 0.563) + 0.0887 × (blasts − 2.10)]. <0.8 low, 0.8–1.2 intermediate, >1.2 high risk.
Key points
- The index predates tyrosine kinase inhibitors, so it is now interpreted alongside the Hasford/Euro, EUTOS, and ELTS scores rather than used in isolation (original synthesis · not guideline verbatim).
- Spleen size is the maximum distance palpable below the costal margin in centimetres, measured before any treatment.
- High-risk patients may be considered for an upfront second-generation TKI or closer molecular monitoring, recognizing the score's limited discrimination in the TKI era.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.