Evidence-based medicine. Part 1: The power and pitfalls of meta-analysis
Evidence-based medicine has challenged opinion-based clinical decision making since the 1990s. Meta-analysis improves statistical power by combining data from more than one study. However, although well conducted meta-analyses sit at the top of the "hierarchy of evidence", poor technique can cause confusion and negatively impact on medicalpractice. The first in a series of articles looking at evidence-basedmedicine, this article explains the method of meta-analysis and demystifies the concept. A recent diabetes meta-analysis is used as an example.