How do systematic literature reviews differ from other reviews?

Systematic literature reviews differ from other types of reviews in their methodology, scope, and rigour. They follow a structured approach with clear research questions, predefined criteria, comprehensive search strategies, and systematic data extraction. Other reviews, like narrative reviews, are more flexible and less structured, often lacking predefined criteria and systematic searches.

Systematic reviews aim to cover all relevant studies on a specific question. In contrast, other reviews may focus on a narrower study scope and include studies selectively, reflecting the author’s perspective. Systematic reviews also employ a systematic search strategy to cover multiple databases and grey literature sources such as government or technical reports, reducing the risk of cherry-picking studies.

Rigor is another key difference. Systematic reviews critically appraise the quality of included studies and often use statistical methods (in the case of quantitative research) or thematic analysis to synthesize findings. Other reviews do not usually include formal quality assessments and rely more on narrative synthesis.

Reproducibility is a hallmark of systematic reviews. They document their process in detail, allowing others to replicate the study. Other reviews often lack this detailed methodology, making replication difficult and leading to potential inconsistencies.

Transparency is crucial in systematic reviews, with published protocols, documented search strategies, and clear study selection processes. Guidelines like the PRISMA checklist (Page et. al 2020) ensure thorough reporting. Other reviews do not usually follow strict guidelines and may not fully disclose their methods and criteria.

The primary objective of systematic reviews is to provide high-quality evidence, informing clinical practice, policy-making, and further research. Other reviews aim to offer overviews or summaries of the literature, providing insights and perspectives rather than systematic evidence synthesis.