Score overt disseminated intravascular coagulation with the ISTH algorithm from platelets, D-dimer, prothrombin time and fibrinogen.
Result
How to use this tool
Use the most recent laboratory count in ×10⁹/L.
Moderate versus strong follows your laboratory reference range and clinical context.
Enter seconds above the laboratory control value, not the absolute time.
A value of 1.0 g/L or below scores 1 point.
Formula & worked example
Platelets 80 (1 point), strong D-dimer increase (3), prothrombin time prolonged by 4 seconds (1) and fibrinogen 1.2 g/L (0) gives 5: overt DIC.
Limitations — read this before you rely on it
Educational aid using the published ISTH overt-DIC algorithm. This tool is for education only and is not medical advice, a diagnosis, or a substitute for professional assessment. It is not a diagnosis and does not replace clinical judgement, repeat laboratory testing or specialist advice.
Frequently asked questions
Disseminated intravascular coagulation is widespread abnormal clotting and bleeding, usually triggered by another serious condition such as sepsis, trauma or malignancy.
No. DIC evolves, so scoring is repeated as labs and the clinical picture change.
It is compatible with overt DIC and needs urgent specialist review, not watchful waiting.
No. It is used only when an underlying DIC-causing disorder is present, alongside clinical judgement.
Fibrinogen is often normal or high early in DIC as an acute-phase reactant, so only a low value scores.