Validation of the IMPROVE bleeding risk score in Chinese medical patients during hospitalization: Findings from the dissolve-2 study

BACKGROUND: Venous thromboembolism (VTE) prophylaxis remains suboptimal in China due to the bleeding risk associated with pharmacologic prophylaxis. We used data from the DissolVE-2 study to report the risk factors for bleeding and validated the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) bleeding risk score (BRS). METHODS: In-hospital major bleeding incidence in medical patients from the DissolVE-2 study were assessed by Kaplan-Meier method. Risk factors associated with clinically relevant bleeding (CRB) were analysed using Cox regression model. Sensitivity, specificity, positive predictive value, negative predictive value and receiver-operating characteristic (ROC) curve was used to compute the diagnostic accuracy of IMPROVE BRS in the study cohort. FINDINGS: Of the 6623 medical patients, 5076 patients with all relevant clinical details were included for the validation cohort. Overall, 127 CRB events (38 major and 89 clinically relevant non-major bleeding events) occurred in this cohort, with a cumulative incidence rate of 2.6% (95% confidence interval [CI], 2.3–3.4). Application of IMPROVE BRS revealed significantly higher hazards of CRB (hazard ratio [HR]: 7.17, 95% CI, 5.05–10.18) and major bleeding (HR: 13.95, 95% CI, 7.28–26.73) in patients with IMPROVE BRS ≥7. Comparison of predictive parameters revealed higher sensitivity (44.1 vs 35.9) and positive predictive value (10.9 vs 2.6) for CRB in our study than the IMPROVE study, which was substantiated by the area under the curve (0.73, p<0.0001) from the ROC curve analysis. INTERPRETATION: IMPROVE BRS is a simple model for estimating bleeding risk in Chinese medical patients and could be used in conjunction with VTE risk assessment models to decide prophylactic treatment for VTE. FUNDING: This study and the additional data analysis were funded by Sanofi (Beijing) Pharmaceutical Co, Ltd by the Fund of The National Key Research and Development Program of China [Grant 2016YFC0905600] and by CAMS Innovation Fund for Medical Sciences (CIFMS) (No.2018-I2M-1–003)