This is an excerpt from a blog originally published on Students 4 Best Evidence
What is a meta-analysis?
Meta-analysis is a statistical technique for combining data from multiple studies on a particular topic.
Meta-analyses play a fundamental role in evidence-based healthcare. Compared to other study designs (such as randomized controlled trials or cohort studies), the meta-analysis comes in at the top of the evidence-based medicine pyramid. This is a pyramid which enables us to weigh up the different levels of evidence available to us. As we go up the pyramid, each level of evidence is less subject to bias than the level below it. Therefore, meta-analyses can be seen as the pinnacle of evidence-based medicine (1).
Meta-analyses began to appear as a leading part of research in the late 70s. Since then, they have become a common way for synthesizing evidence and summarizing the results of individual studies (2).