IMPROVE Bleeding Risk Score Calculator – Hospitalized Patient VTE Prophylaxis

About the IMPROVE Bleeding Risk Score

The IMPROVE Bleeding Risk Assessment Model estimates the risk of in-hospital bleeding in acutely ill hospitalized medical patients. It was derived from the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE), a multinational observational registry.

The original analysis included 10,866 patients who were not actively bleeding at admission and had information available on bleeding during the preceding 3 months. The cumulative incidence of major and clinically relevant nonmajor bleeding within 14 days was 3.2%.

Score components

Risk factor	Criterion	Points
Renal failure	eGFR 30–59	1
Male sex	Male	1
Age	40–84 years	1.5
Current cancer	Present	2
Rheumatic disease	Present	2
Central venous catheter	Present	2
ICU / CCU stay	Present	2.5
Renal failure	eGFR <30	2.5
Hepatic failure	INR >1.5	2.5
Age	≥85 years	3.5
Thrombocytopenia	Platelets <50 × 10⁹/L	4
Recent bleeding	Within 3 months	4
Active gastroduodenal ulcer	Present	4.5

Risk classification

Score	Category	Observed 14-day bleeding incidence*
<7	Lower risk	Major 0.4%; any bleeding 1.5%
≥7	Higher risk	Major 4.1%; any bleeding 7.9%

*Rates reported in the ASH guideline summary of the IMPROVE cohort; they are cohort estimates, not individualized probabilities.

Clinical use

Use this score as one component of an individualized VTE prophylaxis assessment. The ASH guideline supports pharmacological prophylaxis in acutely or critically ill medical inpatients when bleeding risk is acceptable, and mechanical prophylaxis when bleeding risk is unacceptable. The score alone does not determine whether prophylaxis should be given or withheld.

References

Decousus H, Tapson VF, Bergmann JF, et al.; IMPROVE Investigators.Factors at Admission Associated With Bleeding Risk in Medical Patients: Findings From the IMPROVE Investigators. Chest. 2011;139(1):69–79. DOI: 10.1378/chest.09-3081.

Schünemann HJ, et al.; American Society of Hematology.American Society of Hematology 2018 guidelines for management of venous thromboembolism: prophylaxis for hospitalized and nonhospitalized medical patients. Blood Advances. 2018;2(22):3198–3225. DOI: 10.1182/bloodadvances.2018022954.

External Validation of the IMPROVE Bleeding Risk Assessment Model in Medical Patients.External validation study in 12,082 hospitalized medical patients. PubMed record.

Prediction of in-hospital bleeding in acutely ill medical patients: External validation of the IMPROVE bleeding risk score.Thrombosis Research. 2023;230:37–44. DOI: 10.1016/j.thromres.2023.08.003.