Risk assessment models for venous thromboembolism in patients with multiple myeloma: A systematic review and meta-analysis.

Abstract

e24168 Background: Thrombosis prevention is a cornerstone of supportive care in multiple myeloma (MM), as venous thromboembolism (VTE) drives morbidity, treatment interruptions, mortality, and reduced quality of life. The heightened VTE risk in MM arises from patient-, disease-, and treatment-related factors, alongside an increased bleeding risk. Several risk assessment models (RAMs) have been developed to guide thromboprophylaxis, but validation studies show variable performance and heterogeneous designs, limiting generalizability. We conducted a systematic review and meta-analysis to evaluate the predictive performance of available VTE RAMs in adults with MM. Methods: A systematic literature search of Cochrane, Embase, PubMed, and Web of Science was conducted from inception through September 2025. Eligible studies were randomized controlled trials (RCT) or observational studies that externally validated VTE RAMs in adults with MM. Abstract screening, full-text review, and data extraction were performed in duplicate. C-statistics for model discrimination and observed-to-expected (O:E) ratio for model calibration were pooled by random-effects meta-analysis. Heterogeneity was measured with the I 2 statistic. Results: After removal of duplicates, 1,419 records were screened for eligibility, of which 26 were included in the final analysis. Most studies were retrospective cohorts, except for 1 RCT and 2 prospective cohorts. IMPEDE was validated in 21 studies, SAVED in 15 studies, PRISM in 7 studies, and IMWG in 4 studies. Overall, 13,312 individuals were included in this review. Median age ranged from 60 to 75.5 years; proportion of males from 41.5% to 98%; overweight/obesity from 13% to 62%; use of immunomodulatory drugs from 7.3% to 100%; aspirin use from 10.5% to 95.4%; and anticoagulant use from 3.4% to 59.7%. IMPEDE demonstrated the highest pooled discrimination (c-statistic 0.65, 95% CI 0.61–0.69, I 2 = 25%), followed by SAVED (0.60, 95% CI 0.53–0.66, I 2 = 73%), PRISM (0.59, 95% CI 0.47–0.69, I 2 = 69%), and IMWG (0.58, 95% CI 0.50–0.65, I 2 = 0%). Calibration was assessable for IMPEDE and SAVED and was acceptable on average, with pooled O:E ratios of 1.12 (95% CI 0.73–1.72, I 2 = 88%) and 1.06 (95% CI 0.62–1.84, I 2 = 94%), respectively, although CIs were wide. In direct comparisons from seven studies, there was no statistically significant difference in discrimination between IMPEDE and SAVED (pooled c-statistic difference 0.04, 95% CI −0.02 to 0.10, I 2 = 0%). Conclusions: In adults with MM, existing VTE RAMs show only modest discriminative ability, with limited accuracy in distinguishing patients at higher versus lower thrombotic risk, and perform inconsistently across patient populations. Future work should focus on contemporary external validation, improved calibration, as well as refinement or updating of existing models to enhance predictive performance.