University of Birmingham, Birmingham, UK.
Keele University, Keele, UK.
J Thromb Haemost. 2017 Aug;15(8):1591-1600. doi: 10.1111/jth.13739. Epub 2017 Jul 11.
Essentials Correct duration of treatment after a first unprovoked venous thromboembolism (VTE) is unknown. We assessed when restarting anticoagulation was worthwhile based on patient risk of recurrent VTE. When the risk over a one-year period is 17.5%, restarting is cost-effective. However, sensitivity analyses indicate large uncertainty in the estimates.
Background Following at least 3 months of anticoagulation therapy after a first unprovoked venous thromboembolism (VTE), there is uncertainty about the duration of therapy. Further anticoagulation therapy reduces the risk of having a potentially fatal recurrent VTE but at the expense of a higher risk of bleeding, which can also be fatal. Objective An economic evaluation sought to estimate the long-term cost-effectiveness of using a decision rule for restarting anticoagulation therapy vs. no extension of therapy in patients based on their risk of a further unprovoked VTE. Methods A Markov patient-level simulation model was developed, which adopted a lifetime time horizon with monthly time cycles and was from a UK National Health Service (NHS)/Personal Social Services (PSS) perspective. Results Base-case model results suggest that treating patients with a predicted 1 year VTE risk of 17.5% or higher may be cost-effective if decision makers are willing to pay up to £20 000 per quality adjusted life year (QALY) gained. However, probabilistic sensitivity analysis shows that the model was highly sensitive to overall parameter uncertainty and caution is warranted in selecting the optimal decision rule on cost-effectiveness grounds. Univariate sensitivity analyses indicate variables such as anticoagulation therapy disutility and mortality risks were very influential in driving model results. Conclusion This represents the first economic model to consider the use of a decision rule for restarting therapy for unprovoked VTE patients. Better data are required to predict long-term bleeding risks during therapy in this patient group.
在首次无诱因静脉血栓栓塞症（VTE）后至少接受 3 个月抗凝治疗后，尚不确定治疗的持续时间。我们评估了根据患者复发性 VTE 的风险何时重新开始抗凝治疗是有价值的。当一年内的风险为 17.5%时，重新开始抗凝治疗具有成本效益。然而，敏感性分析表明，这些估计存在很大的不确定性。
在首次无诱因静脉血栓栓塞症（VTE）后至少接受 3 个月抗凝治疗后，尚不确定治疗的持续时间。进一步的抗凝治疗降低了发生潜在致命性复发性 VTE 的风险，但代价是出血风险增加，这也可能是致命的。
采用决策规则，根据患者进一步无诱因 VTE 的风险，重新开始抗凝治疗与不延长治疗，进行经济评价，以估计长期成本效益。
基本模型结果表明，如果决策者愿意支付高达 20000 英镑/QALY（质量调整生命年），那么治疗预测 1 年 VTE 风险为 17.5%或更高的患者可能具有成本效益。然而，概率敏感性分析表明，该模型对总体参数不确定性非常敏感，因此在基于成本效益选择最佳决策规则时应谨慎。单变量敏感性分析表明，抗凝治疗不便利性和死亡率等变量对模型结果有很大影响。
这是第一个考虑使用决策规则重新开始治疗无诱因 VTE 患者的经济模型。需要更好的数据来预测该患者群体在治疗期间的长期出血风险。
