Comparative Effectiveness of Treatment Options for Asymptomatic Carotid Disease

描述(由申请人提供)： 对退伍军人保健的预期影响目前还不知道退伍军人医院对无症状颈动脉疾病患者进行了多少次颈动脉内膜剥脱术(CEA)，有多少次是对颈动脉中度狭窄的患者进行的。最重要的是，鉴于医疗管理在过去10年中的进步，目前尚不清楚这些程序对哪些人群的好处大于风险。这个项目将填补我们在CEA方面知识上的这些空白。VA患者将从这项研究中受益，因为更好的信息将支持关于患者水平治疗的更好决策。颈动脉疾病的最佳护理在很大程度上取决于预期寿命和共病负担。这项研究将量化在当前医疗管理实践下，并存条件的存在如何影响CEA的风险和收益。项目背景中风是美国第三大死因，每年约有13.7万人死于中风。颈动脉狭窄是卒中的主要危险因素之一，严重无症状性狭窄患者的年卒中发生率在2%至5%之间。颈动脉内膜切除术(CEA)是最常见的缓解狭窄和预防中风的手术，2006年全美估计有99,000例住院患者进行了颈动脉内膜切除术。CEA也是退伍军人管理局常见的手术方式。我们的研究团队对2009财年VA住院和门诊管理记录进行了初步制表，显示约有10,000名VA患者具有颈动脉狭窄的诊断代码，2,500名患者具有CEA的程序代码。项目目标这个试点提案有两个目标，将支持更大的、未来的提案。目的1.在一个测试年的数据中，确定一组无症状颈动脉疾病的VA患者，他们以前没有进行过颈动脉血运重建术。从放射学数据中提取并编码狭窄率。通过排除最大狭窄在50%以下的人和超过80岁的人来提炼样本。在未来的提案中确定达到足够的预期统计能力所需的数据年数。目的2.在一个测试年的数据中，展示地理实践模式作为医疗中心效应和到最近医疗中心的距离的函数在接受CEA的可能性方面的变化。控制影响CEA选择的已知因素，包括共病负担和最大狭窄程度。项目方法建议的项目是对来自几个来源的次要数据进行的回溯性观察研究。主要数据来源包括来自两个医疗保健系统的患者级别的管理和索赔数据：VA和Medicare。这项研究将利用实践模式的差异来检查哪些治疗对有不同程度颈动脉狭窄和共病负担的患者最有效。使用一个独特的退伍军人全国样本和工具变量分析，我们将检验治疗方法和风险调整后的健康结果之间的因果关系。

DESCRIPTION (provided by applicant): Anticipated Impacts on Veterans' Healthcare At the present time it is not known how many carotid endarterectomy (CEA) procedures are performed in the VA on patients with asymptomatic carotid disease and how many are performed on patients with moderate stenosis of the carotid artery. Most importantly, given the advances in medical management in the last 10 years, it is not known for which subpopulations the benefits of these procedures outweigh the risks. This project would address these gaps in our knowledge with respect to CEA. VA patients would benefit from the study because better information would support improved decision making about patient level treatment. Optimal care for carotid disease depends substantially on life expectancy and comorbidity burden. This research would quantify how the presence of comorbid conditions affects the risks and benefits of CEA under current medical management practices. Project Background Stroke is the third leading cause of death in the United States with about 137,000 deaths attributable to stroke every year. Carotid artery stenosis is one of the principal risk factors for stroke, and patients with severe asymptomatic stenosis have annual stroke rates between 2% and 5%. Carotid endarterectomy (CEA) is the most common procedure performed to alleviate stenosis and prevent stroke with an estimated 99,000 inpatient endarterectomies performed throughout the US in 2006. CEA is also a common procedure performed in the VA. A preliminary tabulation of VA inpatient and outpatient administrative records from FY2009 performed by our study team revealed approximately 10,000 unique VA patients with diagnosis codes for carotid stenosis and 2,500 with procedure codes for CEA. Project Objectives This pilot proposal has two objectives that will support a larger, future proposal. Objective 1. In one test year of data, identify a cohort of VA patients with asymptomatic carotid disease who had no prior carotid revascularization procedures. Extract and code stenosis rates from radiology data. Refine the sample by excluding those with maximum stenosis under 50%, and those over age 80. Determine number of years of data needed to achieve adequate expected statistical power in future proposal. Objective 2. In one test year of data, demonstrate geographic practice pattern variation in likelihood of receiving CEA as a function of medical center effects and distance to the nearest medical center. Control for known factors affecting choice of CEA including comorbidity burden and degree of maximum stenosis. Project Methods The proposed project is a retrospective observational study of secondary data from several sources. Primary data sources include patient-level administrative and claims data from two healthcare systems: VA and Medicare. This study will capitalize on variation in practice patterns to examine which treatments are most effective in patients with varying degrees of carotid stenosis and comorbidity burden. Using a unique national sample of veterans and instrumental variables analysis we will examine the causal relationship between treatment approach and risk-adjusted health outcomes.