OPTIMAL ANTITHROMBOTIC THERAPY IN ATRIAL FIBRILLATION

尽管临床试验表明，抗血栓治疗可以降低精心挑选的房颤（AF）患者中风的风险，但许多患者由于年龄大、合并症或两者兼而有之而被排除在这些试验之外。排除高龄患者导致对75岁以上患者中风预防的有效性和安全性存在不确定性。为了解决现有数据的不足，我们将比较3600名患有房颤的医疗保险受益人在出院时服用华法林或阿司匹林或两者都不服用的结果。在与5家同行评审组织（pro）的合作中，我们将使用医疗保险A部分索赔数据来确定处方抗血栓治疗如何影响死亡率、中风和出血的发生率。拟议研究的广泛、长期目标是降低房颤患者的死亡率并改善其生活质量。为了实现这一双重目标，该研究有3个具体目标：(1)确定在老年房颤患者中开处方抗血栓治疗的有效性；(2)确定高龄房颤患者抗栓治疗的安全性；(3)对高龄房颤患者处方抗栓治疗进行正式的成本效益分析。为了评估有效性，我们将确定抗栓治疗如何影响死亡率或非致死性卒中的发生率。为了评估安全性，我们将确定抗血栓治疗如何影响大出血的发生率。为了进行成本效益分析，我们将在决策模型中使用观察到的死亡率、中风率和出血率来评估抗血栓治疗对质量调整生存率和成本的影响。我们的初步研究结果与其他文献相结合，表明拟议的项目具有挽救生命、预防中风和减少医疗保健支出的潜力。在我们的初步研究中，我们发现抗血栓治疗导致的死亡和非致死性中风的绝对减少可能在75岁以上的患者中最大。如果拟议的项目证实了试点研究的结果，它将澄清处方抗血栓治疗的风险和好处，并阐明这一不断增长的人群的最佳中风预防。

Although clinical trials demonstrated that antithrombotic therapy can reduce the risk of stroke in carefully selected patients with atrial fibrillation (AF), many patients were excluded from these trials because of their advanced age, comorbid conditions, or both. Exclusion of the very elderly has led to uncertainty about the effectiveness and safety of stroke prophylaxis for patients older than 75 years. To address the shortcoming of available data, we will compare outcomes in a cohort of 3600 Medicare beneficiaries with AF who were prescribed warfarin, aspirin, or neither upon hospital discharge. In collaboration with 5 Peer Review Organizations (PROs) we will use Medicare Part A claims data to determine how prescribing antithrombotic therapy affects the rates of death, stroke, and hemorrhage. The broad, long-term objective of the proposed study is to decrease the mortality and improve the quality of life of patients who have AF. In pursuit of this dual objective, the study has 3 specific aims: (l) to determine the effectiveness of prescribing antithrombotic therapy in very elderly patients with AF; (2) to determine the safety of prescribing antithrombotic therapy in very elderly patients with AF; and (3) to conduct a formal cost-benefit analysis of prescribing antithrombotic therapy in very elderly patients with AF. To assess effectiveness, we will determine how antithrombotic therapy affects the rate of death or nonfatal stroke. To assess safety, we will determine how antithrombotic therapy affects the rate of major hemorrhage. To perform the cost-benefit analysis we will use the observed rates of death, stroke, and hemorrhage in a decision model to estimate the effect of antithrombotic therapy on quality- adjusted survival and costs. Results from our pilot study, in combination with other literature, demonstrate that the proposed project has potential to save lives, prevent strokes, and reduce health care expenditure. In our pilot study we found that the absolute reduction in death and nonfatal stroke attributable to antithrombotic therapy may be greatest in patients older than 75. If the proposed project confirms the results of the pilot study, it will clarify the risks and benefits of prescribing antithrombotic therapy to the very elderly and elucidate the optimal stroke prophylaxis for this growing population.