Which type of study involves analyzing data from multiple studies?

The type of study that involves analyzing data from multiple studies is a meta-analysis. This approach synthesizes quantitative data from various independent research studies, allowing for a comprehensive assessment of the overall findings. By aggregating results, meta-analysis increases statistical power and enhances the reliability of conclusions drawn about a particular topic, intervention, or treatment effect. It also helps to identify patterns or discrepancies among study outcomes, which can further guide clinical practice and inform future research.

Systematic reviews are closely related, as they often lay the groundwork for a meta-analysis by collecting and critically evaluating existing studies on a specific question. However, a systematic review may not always involve a quantitative synthesis, making it distinct from meta-analysis, which explicitly combines numerical data.

Randomized controlled trials and cohort studies are types of primary research that usually focus on a single study's methodology rather than analyzing multiple studies simultaneously.