Background: Medical inpatients are at increased risk of venous thromboembolism (VTE) which can be life-threatening or result in chronic complications. Thromboprophylaxis reduces the risk of VTE but incurs costs and potentially increases the risk of bleeding. Risk assessment models (RAMs) are currently used to target thromboprophylaxis at higher risk medical inpatients. It is currently uncertain whether this individualised approach is cost effective.
Aims: To determine the balance of costs, risks, and benefits for different thromboprophylaxis strategies in hospitalised medical inpatients.
Methods: Decision-analytic modelling to estimate the following outcomes for alternative thromboprophylaxis strategies: thromboprophylaxis usage, VTE incidence and treatment, major bleeds including intracranial haemorrhage, chronic thromboembolic complications, and overall survival. We used model parameters from the published literature and evaluated costs over a life time horizon.
We included adult medical inpatients other than those requiring critical care admission. Key interventions evaluated included no thromboprophylaxis, thromboprophylaxis for all and and thromboprophylaxis given according to RAMs. Key outcome measures included costs and quality-adjusted-life-years (QALYs).
Results: Our base case results showed that thromboprophylaxis for all has a high probability (>99%) of being the most cost-effective strategy (£20,000 per QALY threshold) when applying RAM performance data typical of that observed across several RAMs in a cohort of medical inpatients. A sensitivity analysis showed that targeting thromboprophylaxis using a Padua score ≥3 (84% of cohort) has a 76.6% probability of being the most cost-effective strategy when assuming higher RAM performance (sensitivity 99.9%; specificity 23.7%).
Conclusion(s): Thromboprophylaxis for all appears to be the most cost-effective strategy for medical inpatients. A cost-effective RAM would need to have high sensitivity and identify low risk patients who could forego thromboprophylaxis.
Table
Table 1: Base-case results and scenario analysis results for the Padua RAM -mean from 10,000 PSA samples-
Figure
Figure 1: Cost-effectiveness plane for five RAMs validated in a single cohort of medical inpatients -1,2- and for the Padua RAM from an alternative study using a mixed cohort of medical and surgical patients -3-.
To cite this abstract in AMA style:
Horner D, Davis S, Goodacre S, Pandor A, Holland M, de Wit K, Hunt B, Griffin X. Decision-analysis modelling of effectiveness and cost-effectiveness of thromboprophylaxis for medical inpatients [abstract]. https://abstracts.isth.org/abstract/decision-analysis-modelling-of-effectiveness-and-cost-effectiveness-of-thromboprophylaxis-for-medical-inpatients/. Accessed August 16, 2022.« Back to ISTH 2022 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/decision-analysis-modelling-of-effectiveness-and-cost-effectiveness-of-thromboprophylaxis-for-medical-inpatients/