For healthcare professionals
ISTH overt DIC score
The International Society on Thrombosis and Haemostasis (ISTH) overt DIC score adds four routine laboratory tests to judge whether a patient with a known trigger has overt disseminated intravascular coagulation. This tool is written for clinicians. It is not a self-check.
Enter the results
For a patient in hospital. Nothing you enter leaves this page.
What you will see
The ISTH overt DIC score from 0 to 8, the points for each test and whether the total reaches the overt DIC mark of 5.
Educational only, not medical advice. A score never replaces the judgment of the treating team.
Source
ISTH overt DIC score by Taylor and colleagues for the ISTH Scientific Subcommittee on DIC, Thrombosis and Haemostasis 2001, with the points as printed in Table 1 of the open access review by Iba and colleagues, Journal of Intensive Care 2023 (CC BY 4.0), and in the Methods of Tonai and colleagues, BMC Anesthesiology 2022 (CC BY 4.0), checked against Zhao and colleagues, Journal of Intensive Care 2014 (CC BY 4.0), and Franchini and colleagues, Thrombosis Journal 2006 (CC BY 2.0). The wording on this page is our own. The tests check every band edge, the overt DIC mark of 5 and the maximum of 8.
Validated in
We cite the 2001 ISTH paper but do not quote it, because its license does not allow reuse here. The open studies used the score in hospital patients: Tonai and colleagues in patients older than 19 with sepsis in a university hospital intensive care unit, and Zhao and colleagues in patients with systemic inflammation after cardiac surgery.
Limits
Franchini and colleagues note that the score needs an underlying disorder known to be associated with DIC; without one it should not be used. They list disorders that can trigger DIC, including sepsis, severe infections, cancers, and obstetric or vascular disorders. What counts as a moderate or strong increase in the fibrin-related marker depends on the assay and is not one fixed number. The open texts print the prothrombin time item as seconds of prolongation. Older texts print the bands with strict signs (over 3 s, under 100) and leave the exact edges open; this tool uses the bands printed by Iba 2023 and Tonai 2022 (3 to under 6 s, 50 to under 100). Iba 2023 prints the fibrinogen unit as g/mL; Tonai 2022 prints 100 mg/dL and Zhao 2014 1.0 g/L, which is what this tool uses. The sources cited here do not give a death rate for each score, so this page does not show one.
The score, step by step
Points as printed in Iba 2023 and Tonai 2022 (Iba 2023) (Tonai 2022), the same in Zhao 2014 and Franchini 2006 (Zhao 2014) (Franchini 2006):
| Test | Result | Points |
|---|---|---|
| Platelet count (x 10^9/L) | 100 or more | 0 |
| 50 to under 100 | 1 | |
| Under 50 | 2 | |
| Fibrin-related marker (D-dimer, FDP) | No increase | 0 |
| Moderate increase | 2 | |
| Strong increase | 3 | |
| Prothrombin time prolongation | Under 3 seconds | 0 |
| 3 to under 6 seconds | 1 | |
| 6 seconds or more | 2 | |
| Fibrinogen | 100 mg/dL (1.0 g/L) or more | 0 |
| Below 100 mg/dL (1.0 g/L) | 1 |
The total ranges from 0 to 8 (Taylor 2001). As one example of assay cut-offs, Tonai and colleagues counted an FDP of 10 to under 25 µg/mL as a moderate increase and 25 µg/mL or more as a strong increase (Tonai 2022). Worked example: a platelet count of 80 (1), a strong increase in D-dimer (3) and a prothrombin time prolonged by 4 seconds (1), with fibrinogen of 150 mg/dL (0), give 1 + 3 + 1 + 0 = 5.
Reading the result
A total of 5 or more is compatible with overt DIC (Zhao 2014) (Franchini 2006). Franchini and colleagues report that the sensitivity and specificity of the score are high, over 90%, in the studies they reviewed (Franchini 2006). For sepsis, Iba and colleagues also describe the ISTH sepsis-induced coagulopathy (SIC) criteria, built to find patients earlier, before overt DIC (Iba 2023); use the SIC score calculator for those.
Related tools
The Japanese criteria built for acute care, which count the SIRS score, are in the JAAM DIC score. For a low platelet count on heparin, see the 4Ts score. For organ failure in sepsis, use the SOFA score or, outside the ICU, the qSOFA score. Other bedside scores are listed under For healthcare professionals.
Sources
- Iba T, Helms J, Connors JM, Levy JH. The pathophysiology, diagnosis, and management of sepsis-associated disseminated intravascular coagulation. J Intensive Care. 2023;11:24. doi:10.1186/s40560-023-00672-5. Open access (CC BY 4.0). Table 1: ISTH overt DIC, JAAM DIC and SIC scoring systems. pmc.ncbi.nlm.nih.gov/articles/PMC10202753/
- Tonai K, Katayama S, Koyama K, et al. Association between hypomagnesemia and coagulopathy in sepsis: a retrospective observational study. BMC Anesthesiol. 2022;22:359. doi:10.1186/s12871-022-01903-2. Open access (CC BY 4.0). Methods: ISTH overt DIC score. pmc.ncbi.nlm.nih.gov/articles/PMC9685885/
- Zhao D, Zhou J, Haraguchi G, et al. Procalcitonin for the differential diagnosis of infectious and non-infectious systemic inflammatory response syndrome after cardiac surgery. J Intensive Care. 2014;2:35. doi:10.1186/2052-0492-2-35. Open access (CC BY 4.0). Methods: DIC score. pmc.ncbi.nlm.nih.gov/articles/PMC4424708/
- Franchini M, Lippi G, Manzato F. Recent acquisitions in the pathophysiology, diagnosis and treatment of disseminated intravascular coagulation. Thromb J. 2006;4:4. doi:10.1186/1477-9560-4-4. Open access (CC BY 2.0). Diagnosis of DIC: ISTH scoring system. pmc.ncbi.nlm.nih.gov/articles/PMC1402263/
- Taylor FB Jr, Toh CH, Hoots WK, Wada H, Levi M. Towards definition, clinical and laboratory criteria, and a scoring system for disseminated intravascular coagulation. Thromb Haemost. 2001;86(5):1327-1330. doi:10.1055/s-0037-1616068. Original ISTH overt DIC score (cited, not quoted). pubmed.ncbi.nlm.nih.gov/11816725/
Written and maintained by the uncovermyrisk.com editorial team. We do not have a medical reviewer; every claim links to its primary source above. Last reviewed: 2026-11-03. Spotted an error? See About.