A meta-analysis is a statistical technique for combining the results from independent studies that have all looked at the same question. It’s often used to assess the clinical effectiveness of treatments. The value of a meta-analysis depends on the quality of the studies included in the review. Meta-analyses are often considered among the most reliable types of research studies in terms of how confident one can feel about the conclusions. However, this is only the case if they have been conducted rigorously and used criteria that include appropriate studies and exclude inappropriate ones (without excluding appropriate ones).
