01606nas a2200157   4500000000100000008004100001653001700042653001900059653002800078100001500106700001500121245023400136300001100370490000600381520106100387       1999                            d10aHypertension10aBlood Pressure10aCardiovascular Diseases1 aNeal Bruce1 aMacmahon S00aThe World Health Organization--International Society of Hypertension Blood Pressure Lowering Treatment Trialists' Collaboration: prospective collaborative overviews of major randomized trials of blood pressure-lowering treatments  a346-560 v13 a<p>
Clear evidence shows that decreasing blood pressure reduces risks for major cardiovascular events in patients with hypertension. However, there is considerable uncertainty about the separate effects of the various classes of blood pressure-lowering agents and the effects of blood pressure lowering in patients at high risk, particularly in the absence of hypertension. Several new randomized controlled trials have been started in the past few years in an effort to address these questions. However, individually, these studies are unlikely to resolve all current uncertainties. For this reason, systematic overviews and meta-analyses of the major ongoing trials are planned. The overviews will be conducted as a collaboration among the principal investigators of the participating trials and will involve about 270,000 patients and 1.1 million patient-years of follow-up. The combined trial results should provide good statistical power to detect even modest differences in the effects of various treatments on major cardiovascular outcomes.
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