What distinguishes a systematic review?

A systematic review is distinguished by its rigorous and structured methodology that includes a comprehensive summary of existing literature, utilizing clearly defined and reproducible methods. This approach emphasizes transparency, allowing for the replication of the review process and ensuring that it minimizes biases in study selection and analysis.

The clarity in methods is essential because it not only aids in the credibility of the findings but also allows other researchers to follow the same systematic process to verify results or build upon them in future research. The systematic nature of reviews encompasses several key components, such as a clearly formulated research question, meticulous selection criteria, and a thorough search strategy, all leading to a cohesive synthesis of evidence that ideally informs practice or policy.

Other options present characteristics that do not appropriately define a systematic review. The critical approach to sample size determination may be relevant in primary research but does not define a systematic review. Similarly, a lack of predefined search methods contradicts the very principle of a systematic review, which relies on explicit searching strategies to ensure that all relevant studies are considered. Finally, while both qualitative and quantitative studies can be included in systematic reviews, the focus is not strictly on qualitative data; systematic reviews can synthesize findings from both types of research, depending on the research question being addressed.