Global variation in thromboprophylaxis models of care and implementation supports for hospitalized and ambulatory cancer care.

Abstract

e13627 Background: Cancer-associated thrombosis (CAT) is a leading cause of morbidity and mortality. As systemic therapies increasingly shift to ambulatory delivery—where most venous thromboembolism (VTE) events occur—effective models of care for thromboprophylaxis beyond the inpatient setting are critical. An expanding evidence base and evolving guidelines support risk-directed thromboprophylaxis across care settings, highlighting the importance of understanding real-world implementation. However, how thromboprophylaxis is operationalized globally—particularly in ambulatory cancer care—remains poorly described. Methods: A global, cross-sectional assessment of institutional thromboprophylaxis models of care for hospitalized and ambulatory adults with cancer was conducted in Q2 2025, with one response per service from oncology or antithrombotic pharmacists. Institution-level data on guideline availability, VTE risk assessment and prescribing workflows, preferred antithrombotics, and implementation barriers were collected and analyzed descriptively. Denominators reflect eligible responses per item. Results: Models of care were reported for 96 health services across Asia (27.1%), North America (27.1%), Oceania (20.8%), Europe (14.6%), and other regions (10.4%). Institutional CAT guidelines were available in 56.8% of hospitalized and 38.6% of ambulatory settings, with highest availability in Europe (85.7% hospitalized; 66.7% ambulatory). Risk assessment and prescribing occurred across multiple systems in 34.4% of institutions, most frequently in Latin America/Middle East/Africa (90%). For hospitalized patients, thromboprophylaxis strategies were evenly split between opt-out (default unless contraindicated; 48.8%) and opt-in (criteria-based; 51.2%), with regional variation (Oceania 83.3% opt-out; Europe/Asia 66.7% opt-in; North America 50/50). Ambulatory practices were inconsistent: VTE risk assessment was recommended for select patients in 30.4% of centers and not performed in 39.1%. System-level decision support was reported less often for ambulatory than hospitalized care (25.3% vs 62.2%). Oral anticoagulants were guideline-recommended more often in ambulatory than hospitalized care (68.8% vs 33.3%); apixaban more than rivaroxaban (71.9% vs 46.9%). Quality monitoring for ambulatory CAT was uncommon, with ≤15% of services routinely tracking risk assessment, prophylaxis use, or VTE rates. Barriers included limited pharmacist involvement (absent in 19.5% of ambulatory settings), fragmented systems, and variable anticoagulant availability. Conclusions: Global models of care for thromboprophylaxis vary substantially, with implementation less mature and less supported in ambulatory than hospitalized cancer care, underscoring the need for system-level implementation strategies in outpatient oncology.