J Hypertens. 1998 Feb;16(2):127-37.
To conduct prospectively planned overviews (meta-analyses) of the ongoing randomized trials of blood-pressure-lowering drugs. These overviews should provide reliable data about the effects of newer classes of blood-pressure-lowering drugs (such as angiotensin converting enzyme inhibitors and calcium antagonists) on major causes of cardiovascular mortality and morbidity for a variety of patient groups.
A registry of major ongoing or planned randomized trials (with more than 1000 patient-years of follow-up for each randomized group) of blood-pressure-lowering agents has been established. The principal investigators of each of these studies have been invited to collaborate in the project and to provide, upon completion of the study, a limited data set for inclusion in the overview analyses. The principal comparisons will be of newer versus older classes of blood-pressure-lowering drugs in treating patients with hypertension and of newer blood-pressure-lowering treatments versus untreated or less treated control conditions for a variety of other groups of patients with a high risk of cardiovascular events. Separate analyses will be conducted for the main drug classes and for major subgroups of patients defined by characteristics such as age, gender, blood pressure, diabetes, and history of renal disease, coronary heart disease or cerebrovascular disease. The principal study outcomes are stroke, major coronary heart disease events, heart failure, total cardiovascular deaths, total cardiovascular events and total mortality.
In total 36 trials of blood-pressure-lowering treatments potentially eligible for inclusion in this project have been identified and agreement to collaborate has been confirmed by the investigators in 30 trials, with collaboration pending for six recently identified studies. The first round of analyses will be conducted in 1999 and will be based on total cardiovascular events observed among a total of about 64,000 patients, involving about 240,000 patient-years of follow-up. The second round of analyses will be conducted in 2003 on data from at least 195,000 patients and 899,000 patient-years of follow-up. By that time it is estimated that a total of about 8000 strokes, 12,000 coronary heart disease events and 23,000 cardiovascular events in total will have occurred. This should provide good statistical power to detect even modest cause-specific differences in the incidence of the main study outcomes.
The combination of trial results in prospectively planned, systematic overviews both reduces random errors and avoids biases. As a consequence, this project should provide more reliable information about the effects of newer blood-pressure-lowering drugs than would any one study alone. The use of data from individual patients in these overviews will facilitate investigation of the separate effects of various drug regimens in treating members of major patient subgroups.
对正在进行的降血压药物随机试验进行前瞻性规划的综述（荟萃分析）。这些综述应提供关于新型降血压药物（如血管紧张素转换酶抑制剂和钙拮抗剂）对各类患者群体心血管疾病死亡率和发病率主要病因影响的可靠数据。
已建立一个正在进行或计划中的主要降血压药物随机试验登记册（每个随机分组的随访时间超过1000患者年）。已邀请这些研究的主要研究者参与该项目，并在研究完成后提供有限的数据集以纳入综述分析。主要比较将是新型与旧型降血压药物治疗高血压患者的效果，以及新型降血压治疗与未治疗或治疗较少的对照情况对各类心血管事件高风险患者群体的效果。将针对主要药物类别以及按年龄、性别、血压、糖尿病、肾病、冠心病或脑血管疾病史等特征定义的主要患者亚组进行单独分析。主要研究结局为中风、主要冠心病事件、心力衰竭、心血管总死亡、心血管总事件和总死亡率。
总共已识别出36项可能符合纳入本项目条件的降血压治疗试验，30项试验的研究者已确认同意合作，6项最近识别出的研究的合作事宜正在商讨中。第一轮分析将于1999年进行，将基于总共约64000名患者中观察到的心血管总事件，涉及约240000患者年的随访。第二轮分析将于2003年根据至少195000名患者的数据和899000患者年的随访进行。到那时，估计总共将发生约8000例中风、12000例冠心病事件和23000例心血管事件。这应提供良好的统计效力，即使是检测主要研究结局发生率中适度的病因特异性差异。
在进行前瞻性规划的系统综述中合并试验结果既减少了随机误差又避免了偏差。因此，本项目应能提供比任何一项单独研究更可靠的关于新型降血压药物效果的信息。在这些综述中使用个体患者的数据将有助于研究各种药物方案对主要患者亚组成员的单独治疗效果。
