ISTH DIC Score

Name: ISTH DIC Score calculator — MedScore
Creator: Nabil Alzein

ISTH overt disseminated intravascular coagulation score — only for a patient with an underlying disorder known to be associated with DIC

Platelet count (×10³/µL = ×10⁹/L)

≥ 100

50 to < 100

< 50

Fibrin-related marker (e.g. D-dimer, fibrin degradation products)

No increase

Moderate increase

Strong increase

Prolongation of prothrombin time (above the upper reference limit)

< 3 seconds

≥ 3 to < 6 seconds

≥ 6 seconds

Fibrinogen

≥ 1 g/L (≥ 100 mg/dL)

< 1 g/L (< 100 mg/dL)

About this score

When to use

Scores overt disseminated intravascular coagulation from platelet count, a fibrin-related marker, prothrombin time prolongation and fibrinogen. ⁦[1]⁩

Pearls and pitfalls

It applies only in the presence of an underlying disorder associated with overt DIC; 5 or more is compatible with overt DIC and is re-scored daily, below 5 suggests non-overt DIC. ⁦[2]⁩

Summarised from the numbered sources under Evidence. Check the source before relying on a statement.

Evidence

[1] Original publication

Taylor FB Jr, Toh CH, Hoots WK, Wada H, Levi M; Scientific Subcommittee on DIC of the ISTH. Towards definition, clinical and laboratory criteria, and a scoring system for disseminated intravascular coagulation. Defines the overt-DIC score from platelet count, a fibrin-related marker, prothrombin time prolongation and fibrinogen.

Thrombosis and Haemostasis, 2001

Open source

[2] Validation

Toh CH, Alhamdi Y, Abrams ST. Current pathological and laboratory considerations in the diagnosis of disseminated intravascular coagulation. Table 1 reproduces the ISTH criteria used here: apply only with an underlying disorder associated with overt DIC; ≥ 5 compatible with overt DIC (repeat scoring daily); < 5 suggestive of non-overt DIC (repeat within 1–2 days).

Annals of Laboratory Medicine, 2016

Open source

Last reviewed: 2026-10

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MedScore is an educational and clinical decision-support tool. It does not provide a diagnosis, a treatment, or a drug-dosing recommendation, and it does not replace clinical judgement or local guidelines. Confirm every result against the original source before acting on it. The treating clinician remains responsible for all decisions.