What is a key component often included in systematic reviews?

A systematic review is a rigorous process that synthesizes research findings from multiple studies in a specific area. One of the key components typically included in systematic reviews is meta-analysis. This statistical method allows researchers to combine data from several independent studies to identify overall trends and draw more robust conclusions. By aggregating results, meta-analysis enhances the statistical power and provides a clearer understanding of the effects being studied.

Meta-analysis is distinct because it not only summarizes the evidence but also quantifies the results, allowing for the evaluation of consistency or variability across different studies. This is particularly crucial in fields where variability in study results can lead to different interpretations or clinical guidelines.

The other options, while they may play roles in research or other forms of literature, do not represent the primary analytical component of systematic reviews. For instance, qualitative analysis focuses on non-numerical data and is often not part of the systematic review's quantitative approach. Case reports provide anecdotal evidence from individual cases and lack the comprehensive review of literature found in systematic reviews. Editorial comments are opinion pieces that express personal or professional viewpoints rather than established research findings.