Venous thromboembolism (VTE) is a major preventable cause of morbidity and mortality in hospitalized medical patients. Current recommendations support broad pharmacologic thromboprophylaxis, while individualized risk assessment may help refine prescribing. The IMPROVE VTE and IMPROVE Bleeding scores provide standardized risk assessment tools but should complement, rather than replace, clinical judgment.

To evaluate the discrepancy between real-world thromboprophylaxis prescribing and a prespecified sequential IMPROVE-based strategy and assess its economic and environmental implications.

We conducted a single-center retrospective cohort study in internal medicine over one month. Adults hospitalized for > 48 h were included, excluding those receiving therapeutic anticoagulation. IMPROVE VTE and Bleeding scores were calculated retrospectively. Pharmacologic prophylaxis was supported by the strategy for patients with an IMPROVE Bleeding score < 7 and IMPROVE VTE score ≥ 2. Observed prescriptions were compared with the prespecified strategy using contingency analysis and Fisher's exact test.

Among 99 patients, 79.8% received pharmacologic thromboprophylaxis, whereas 46.5% met the strategy criteria. Among treated patients, 46.8% did not meet these criteria. Strict application of the strategy would theoretically result in 292 fewer doses over one month, corresponding to €233.60 in estimated savings and approximately 405 kg CO ₂ eq.

Real-world prescribing differed substantially from the prespecified strategy. Strict application would theoretically reduce anticoagulant use, costs, and carbon emissions. However, clinical outcomes were not assessed, and RAMs should complement rather than replace clinical judgment. Prospective studies incorporating VTE and bleeding outcomes are required to assess the safety of this approach.