Which category does a systematic review fall under?

A systematic review falls under the category of secondary evidence because it synthesizes and analyzes data from multiple primary research studies to draw broader conclusions about a specific research question. In a systematic review, researchers gather all relevant studies on a topic, critically evaluate their methodologies, and summarize findings to provide an overview of existing evidence. This process not only highlights trends and gaps in the research but also helps identify patterns that may not be evident in individual studies.

By contrast, primary evidence comes from original research conducted by the investigator and typically includes randomized controlled trials, cohort studies, or case studies. Tertiary evidence includes summaries or compilations of primary and secondary evidence, such as textbooks or encyclopedias. Experimental evidence refers specifically to findings from carefully designed experiments, often involving controlled conditions. Systematic reviews, as secondary evidence, are invaluable for guiding practice as they distill complex information from multiple sources into actionable insights.