National trends and inpatient outcomes of venous thromboembolism in hospitalized acute leukemia: a propensity-score weighted analysis, 2016–2022

Venous thromboembolism (VTE) is a recognized complication of acute leukemia, yet its national prevalence, temporal trends, and associations with inpatient outcomes remain poorly characterized. We aimed to provide a contemporary, nationally representative analysis of VTE burden and outcomes among hospitalized adults with acute leukemia. We conducted a retrospective analysis of the National Inpatient Sample (NIS, 2016–2022). Adult hospitalizations with a principal diagnosis of acute leukemia were identified using ICD-10-CM codes. VTE was the primary exposure. The primary outcome was any blood product transfusion. Transfusion was selected as the primary outcome because acute leukemia is characterized by a complex balance between thrombosis, thrombocytopenia, bleeding risk, and supportive transfusion requirements, making transfusion use a clinically relevant marker of this competing thrombohemorrhagic burden; secondary outcomes included in-hospital mortality, length of stay (LOS), and inflation-adjusted hospital charges. Multivariable regression models accounted for the complex NIS survey design. Temporal trends were assessed using predictive margins. Propensity-score weighted (PSW) sensitivity analyses using ATT weights evaluated the robustness of primary findings. Among 191,640 weighted hospitalizations, 8,880 (4.6%) had VTE. Adjusted VTE prevalence increased significantly between 2016 and 2022 ( p = 0.032), and peaked at 5.3% in 2021. After multivariable adjustment, VTE was independently associated with lower odds of blood product transfusion (aOR 0.842; 95% CI, 0.761–0.932; p = 0.001), higher in-hospital mortality (aOR 1.478; 95% CI, 1.276–1.711; p < 0.001), longer LOS (β, 8.41 days; p < 0.001), and higher hospital charges (β, $127,633; p < 0.001). All associations remained stable in PSW sensitivity analyses. VTE was identified in approximately 1 in 22 hospitalizations of adults with acute leukemia, and its prevalence rose significantly over the study period. VTE was independently associated with higher mortality, prolonged hospitalization, and greater hospital charges. The paradoxical inverse association with transfusion may reflect unmeasured disease severity and competing thrombohemorrhagic risks.