Stroke. 1989 Jul;20(7):844-9. doi: 10.1161/01.str.20.7.844.
This report summarizes the study design and organization of a multicenter, randomized trial of carotid endarterectomy for the treatment of asymptomatic carotid stenosis. The Asymptomatic Carotid Atherosclerosis Study will determine whether the addition of carotid endarterectomy to aspirin plus risk factor modifications affects the incidence of ipsilateral transient ischemic attack, amaurosis fugax, and retinal and cerebral infarction in patients with asymptomatic hemodynamically significant carotid stenosis in at least one artery. Power calculations are based on assumptions of alpha = 0.05 (two-sided test) with annual event rate 3% transient ischemic attack and 1% cerebral infarction per year. The study has 90% power for detection of a 25% difference in events in a 5-year study. Two continuous validation programs are in use: a Doppler/angiogram correlation study for each Doppler instrument used in screening potential candidates and a transient ischemic attack/stroke questionnaire/validation study for verification of end points. Quality assurance is a major component in study design.
本报告总结了一项多中心随机试验的研究设计与组织情况，该试验旨在探讨颈动脉内膜切除术治疗无症状性颈动脉狭窄的效果。无症状性颈动脉粥样硬化研究将确定在阿司匹林治疗及危险因素控制基础上加行颈动脉内膜切除术，是否会影响至少一条动脉存在无症状性血流动力学显著颈动脉狭窄患者同侧短暂性脑缺血发作、一过性黑矇、视网膜及脑梗死的发生率。效能计算基于α=0.05（双侧检验）的假设，年事件发生率为短暂性脑缺血发作3%、脑梗死1%。该研究在为期5年的研究中，检测事件发生率25%差异的效能为90%。目前正在使用两个连续验证程序：一个是针对用于筛选潜在受试者的每台多普勒仪器的多普勒/血管造影相关性研究，另一个是用于终点验证的短暂性脑缺血发作/中风问卷/验证研究。质量保证是研究设计的一个主要组成部分。
