a statistical technique that combines and synthesizes data from multiple independent studies on the same topic to produce a single, more precise estimate of the effect or association. By pooling results, meta-analyses increase statistical power, improve the precision of estimates, and help identify patterns or inconsistencies across studies. Meta-analyses are typically conducted as part of systematic reviews and are widely regarded as a high level of evidence in evidence-based practice.
Example
A team of researchers conducts a meta-analysis of 20 randomized controlled trials evaluating the effectiveness of a new biologic therapy for rheumatoid arthritis. By pooling the data from over 10,000 participants, they find a consistent and statistically significant improvement in disease activity compared to standard treatments, providing a stronger basis for clinical guidelines than any single trial alone.