Meta-analysis is a statistical technique for combining the findings of randomised trials which have addressed the same or a similar scientific question. We are distinctive in that we have established international collaborations of trial investigators who have contributed large datasets of anonymised individual patient data to PHRU’s meta-analysis programmes. These datasets have been processed and analysed to generate some of the world’s largest meta-analyses, which have informed treatment guidelines and influenced the treatment of millions of patients worldwide.
Our work on meta-analysis is divided into two programmes investigating, respectively, treatments for early breast cancer and treatments for the prevention of cardiovascular diseases.
The work we have coordinated in the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) has for several decades been evaluating treatments for early breast cancer, with the aim of assessing the long-term benefits and side-effects of the wide range of treatment options for this condition. Our results are highly cited and widely used in clinical guidelines world-wide, so have made a major contribution to the large falls in worldwide breast cancer mortality.
Similarly, our work in evaluating treatments for vascular disease includes examining the effects of aspirin and other antiplatelet drugs (the Antithrombotic Treatment Trialists’ [ATT] Collaboration). It has shown that in high risk patients aspirin reduces heart attacks and strokes by about a quarter. In healthy people, aspirin is of uncertain net value as its benefits have to be weighed against increased bleeding. The results of the ATT have influenced all of the major international guidelines and are among the most highly cited papers in medicine.