ISTH overt DIC score
Laboratory score for overt disseminated intravascular coagulation
- ISTH SSC on DIC
- Onkopedia Gerinnung (DGHO)
Sources last checked: 2026-10-13
ISTH overt DIC score
Laboratory score for overt disseminated intravascular coagulation
Apply only when an underlying disorder known to cause DIC is present (sepsis, trauma, malignancy, obstetric complications …). 'Moderate' and 'strong' fibrin-marker increases depend on the assay — local D-dimer thresholds apply.
Interpretation
| < 5 — not compatible with overt DIC | Does not exclude a developing (non-overt) coagulopathy; because DIC is dynamic, the score can change over time. |
|---|---|
| ≥ 5 — compatible with overt DIC | DIC is secondary to an underlying disorder and evolves over time; the score is designed for serial reassessment. |
What is the ISTH overt DIC score?
The ISTH overt DIC score combines platelet count, a fibrin-related marker (usually D-dimer), prothrombin-time prolongation and fibrinogen into a 0–8 score; 5 or more is compatible with overt disseminated intravascular coagulation. It was proposed by the ISTH Scientific Subcommittee on DIC in 2001. Onkopedia tabulates a 2025 ISTH update that defines the D-dimer thresholds as multiples of the upper limit of normal.
When to use it
- In a patient with a condition known to cause DIC (sepsis, trauma, malignancy such as APL, obstetric complications)
- To document whether laboratory findings meet overt DIC
- Serially, as DIC evolves over hours to days
When not to use it
- Without an underlying cause of DIC — the score is not a screening test
- In liver failure or on anticoagulants, where PT and fibrinogen are abnormal for other reasons
How it is calculated
| Criterion | Points |
|---|---|
| Platelet count | |
| ≥ 100 ×10⁹/L | 0 |
| 50 to < 100 ×10⁹/L | 1 |
| < 50 ×10⁹/L | 2 |
| Fibrin-related marker (e.g. D-dimer) | |
| No increase | 0 |
| Moderate increase | 2 |
| Strong increase | 3 |
| Prolongation of prothrombin time | |
| < 3 s | 0 |
| 3 to < 6 s | 1 |
| ≥ 6 s | 2 |
| Fibrinogen | |
| ≥ 1.0 g/L | 0 |
| < 1.0 g/L | 1 |
Clinical pearls and limitations
- Apply only when an underlying disorder known to cause DIC is present (sepsis, trauma, malignancy, obstetric complications …). 'Moderate' and 'strong' fibrin-marker increases depend on the assay — local D-dimer thresholds apply.
- The trend matters more than a single value: falling platelets and fibrinogen with rising D-dimer are typical.
- Fibrinogen is an acute-phase protein and can stay normal in septic DIC.
- In sepsis, the ISTH sepsis-induced coagulopathy (SIC) score identifies an earlier stage.
- Which D-dimer levels count as 'moderate' and 'strong' increases is set locally.
Frequently asked questions
What ISTH DIC score means overt DIC?
A total of 5 or more is compatible with overt DIC.
Which fibrin marker should I use?
D-dimer is the most widely available. The 2025 ISTH revision tabulated by Onkopedia scores D-dimer > 3× ULN as 2 points and > 7× ULN as 3 points.
Does a score below 5 exclude DIC?
No. It means overt DIC criteria are not met at that moment; the score can change as the clinical picture evolves.
Evidence and guidelines
- Primary source: 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. Thromb Haemost 2001;86(5):1327-1330.
- Onkopedia (DGHO): Diagnostik von Gerinnungsstörungen — Tabelle 15, Overt-DIC-Score (ISTH, 2025) und SIC-Score.
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