Editorial by Fitzgerald Papers p 71

On p 71 we publish the latest in a series of meta-analyses from the Antithrombotic Trialists' Collaboration. Here John Cleland argues that, despite the vast size of these meta-analyses, the evidence in support of aspirin preventing atherosclerotic events is still inconclusive. One adverse effect of the belief that aspirin is more effective than it is, he argues, is the neglect of more effective drugs for preventing heart disease and stroke.

The third meta-analysis from the Antithrombotic Trialists' Collaboration, published in this issue, contains data on over 100 000 patients at high risk of atherosclerotic events, representing more than 250 000 patient years of follow up.1 This meta-analysis and its predecessors form the major argument for the current widespread fashion of prescribing aspirin to such patients. 2 3 It is an enormous body of research and the collaboration is to be congratulated for having gathered so much data. However, quality as well as quantity matters. And the quality is such that the results can only be inconclusive.