What is the main characteristic of systematic reviews?

Systematic reviews are characterized by their adherence to standardized guidelines and methodologies. This structured approach is essential for ensuring that the review is comprehensive, unbiased, and replicable. By following established protocols—such as those outlined by organizations like PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses)—systematic reviews aim to minimize bias in the selection and analysis of data. These guidelines provide a clear framework for formulating research questions, defining inclusion and exclusion criteria, conducting literature searches, and synthesizing data, which enhances the reliability and validity of the findings.

In contrast, the other characteristics mentioned do not accurately reflect the nature of systematic reviews. They are not highly subjective; rather, they strive for objectivity. Systematic reviews also do not exclusively include only prospective studies, as they can include both prospective and retrospective studies depending on the research question. Lastly, systematic reviews are not focused on summarizing anecdotal evidence; instead, they aim to synthesize evidence from multiple studies to provide a more reliable conclusion based on rigorously collected data.