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）患者的卒中风险，但许多患者因高龄、共病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75岁以上患者预防卒中的有效性和安全性不确定。为了解决现有数据的不足，我们将比较3600名患有AF的医疗保险受益人的队列结果，这些受益人在出院时服用华法林、阿司匹林或两者都不服用。我们将与5个同行评审组织（PRO）合作，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、中风和出血率。本研究的广泛、长期目标是降低房颤患者的死亡率和改善其生活质量。为了实现这一双重目标，本研究有3个具体目标：（1）确定抗血栓治疗对高龄房颤患者的有效性;（2）确定抗血栓治疗对高龄房颤患者的安全性;（3）对高龄房颤患者抗血栓治疗进行正式的成本效益分析。为了评估有效性，我们将确定抗血栓治疗如何影响死亡率或非致命性卒中。为了评估安全性，我们将确定抗血栓治疗如何影响大出血率。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、卒中和出血率来估计抗血栓治疗对质量调整生存率和成本的影响。我们的试点研究结果，结合其他文献，表明拟议的项目有可能挽救生命，预防中风，并减少医疗保健支出。在我们的初步研究中，我们发现抗血栓治疗引起的死亡和非致命性卒中的绝对减少在75岁以上的患者中可能最大。如果拟议的项目证实了试点研究的结果，它将阐明抗血栓治疗的风险和好处，非常老年人和阐明最佳的中风预防这一不断增长的人口。

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.