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. 2024 May 15;8(4):102441.
doi: 10.1016/j.rpth.2024.102441. eCollection 2024 May.

Validation of the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) risk scores for venous thromboembolism and bleeding in an independent population

Katherine S Wilkinson  1 , Andrew D Sparks  2 , Mansour Gergi  3   4 , Allen B Repp  3   4 , Hanny Al-Samkari  5 , Ryan Thomas  3   4 , Nicholas S Roetker  6 , Neil A Zakai  1   4   5
Affiliations

Validation of the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) risk scores for venous thromboembolism and bleeding in an independent population

Katherine S Wilkinson et al. Res Pract Thromb Haemost. .

Abstract

Background: Multiple guidelines recommend assessment of bleeding and venous thromboembolism (VTE) risk in adult medical inpatients to inform prevention strategies. There is no agreed-upon method for VTE and bleeding risk assessment.

Objectives: To validate the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) VTE and bleeding risk scores in an independent population.

Methods: In this retrospective study, we calculated the IMPROVE VTE and bleeding risk scores in medical inpatients admitted between 2010 and 2019 at the University of Vermont Medical Center (UVMMC). Patients were followed for in-hospital bleeding events while hospitalized and VTE events while hospitalized and for 3 months after discharge. We assessed calibration of the risk models by comparing the observed incidence of events in the UVMMC and IMPROVE populations across the published risk categories. We also assessed performance of the IMPROVE risk factors after refitting the models in the UVMMC population. Discrimination was assessed using the area under the receiver operating characteristic curve (AUC).

Results: VTE occurred in 270 (1.1%) of 23,873 admissions, with 92 (34%) occurring during admission, and bleeding occurred in 712 (4.7%) of 15,240 admissions. When the IMPROVE-VTE risk factors were refitted to the UVMMC data, the AUC was 0.64. When the IMPROVE bleeding risk factors were refitted to the UVMMC data, the AUC was 0.67. The IMPROVE-VTE score tended to overestimate risk at higher scores, and the IMPROVE bleeding score underestimated risk at lower scores and overestimated risk at higher scores.

Conclusion: While the refitted IMPROVE VTE and bleeding risk scores had reasonable model fit, the scores were poorly calibrated and did not reliably identify or differentiate patients at risk for VTE and bleeding. Different methods are needed for risk assessment of medical inpatients for VTE and bleeding risk.

Keywords: adult; bleeding; inpatients; risk assessment; venous thrombosis.

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Figures

Figure 1
Figure 1
International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) venous thromboembolism (VTE) and bleeding scores. GFR, glomerular filtration rate; INR, international normalized ratio.
Figure 2
Figure 2
Population flow chart. POA, present on admission; VTE, venous thromboembolism.
See this image and copyright information in PMC

References

    1. Gergi M., Wilkinson K., Koh I., Munger J., Al-Samkari H., Smith N.L., et al. The relative risk of bleeding after medical hospitalization: the medical inpatient thrombosis and hemorrhage study. J Thromb Haemost. 2023;21:513–521. - PMC - PubMed
    1. Lutsey P.L., Zakai N.A. Epidemiology and prevention of venous thromboembolism. Nat Rev Cardiol. 2023;20:248–262. - PMC - PubMed
    1. Jordan Bruno X., Koh I., Lutsey P.L., Walker R.F., Roetker N.S., Wilkinson K., et al. Venous thrombosis risk during and after medical and surgical hospitalizations: the medical inpatient thrombosis and hemostasis (MITH) study. J Thromb Haemost. 2022;20:1645–1652. - PMC - PubMed
    1. United States. Public Health Service . U.S. Public Health Service, Office of the Surgeon General; Rockville, MD: 2008. Office of the Surgeon General. The Surgeon General's call to action to prevent deep vein thrombosis and pulmonary embolism. - PubMed
    1. The Joint Commission Specifications Manual for national hospital inpatient quality measures. 2011. http://www.jointcommission.org/specifications_manual_for_national_hospit... 2011. [accessed June 1, 2023].

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