Calculators & Tools

Sickle Cell — Risk of Severe Disease (Miller)

Predicts later severe sickle-cell disease from events in the first two years of life.

1 What is the Sickle Cell — Risk of Severe Disease (Miller)?

The Sickle Cell — Risk of Severe Disease (Miller) is a haematology scoring tool used in paediatric practice. Predicts later severe sickle-cell disease from events in the first two years of life. It scores 3 criteria and interprets the total across 3 bands, so the number always arrives with the severity it implies rather than on its own. In PediAid each criterion is shown as a labelled option with the weight it carries, so the total can be checked rather than taken on trust.

2 When to use it

  • Grading severity at the bedside in haematology
  • Recording an objective severity band in the case notes
  • Deciding when a total crosses the threshold for escalation
  • Re-scoring to track whether a child is improving or deteriorating
  • Checking the exact criteria of a score used infrequently

3 Formula & method

The score sums 3 criteria: Dactylitis (hand-foot syndrome) before 1 year of age; Haemoglobin < 7 g/dL (baseline, steady state); Leucocytosis in the absence of infection. Totals are then banded: any score - Low risk: no predictors - low probability of severe disease in later childhood. Continue routine care: penicillin prophylaxis, vaccination, TCD screening; 1 risk factor or more - Intermediate: one predictor - intermediate risk. Maintain close follow-up and a low threshold for starting hydroxyurea; 2 risk factors or more - High risk: two or more predictors - high probability of severe disease (adverse outcome by age 10). Strongly consider early hydroxyurea and intensified monitoring.
  • Derived in the Cooperative Study of Sickle Cell Disease infant cohort.
  • Source: Miller ST et al. Prediction of adverse outcomes in children with sickle cell disease. N Engl J Med 2000;342:83-9.

4 Frequently asked questions

How many criteria does the Sickle Cell — Risk of Severe Disease (Miller) use?

3. They are Dactylitis (hand-foot syndrome) before 1 year of age; Haemoglobin < 7 g/dL (baseline, steady state); Leucocytosis in the absence of infection.

What do the bands of the Sickle Cell — Risk of Severe Disease (Miller) mean?

The total is interpreted as: any score - Low risk: no predictors - low probability of severe disease in later childhood. Continue routine care: penicillin prophylaxis, vaccination, TCD screening; 1 risk factor or more - Intermediate: one predictor - intermediate risk. Maintain close follow-up and a low threshold for starting hydroxyurea; 2 risk factors or more - High risk: two or more predictors - high probability of severe disease (adverse outcome by age 10). Strongly consider early hydroxyurea and intensified monitoring.

Does the score replace clinical judgement?

No. It is a structured way to record and communicate severity. A clinician concerned about a child should act on that concern regardless of the total.

Where does this score come from?

Derived in the Cooperative Study of Sickle Cell Disease infant cohort.

Does it work offline?

Yes. Score definitions are bundled with the PediAid app, so the score computes without a connection.

For qualified clinicians. This page and the PediAid app are a clinical aid only. Calculations and reference data must be verified against the patient's clinical context, the source guideline and your local protocols before any treatment decision is made.