When conducting academic research, particularly in the health, social sciences, and evidence-based disciplines, two common review types often come up: the systematic review and the literature review. While they may seem similar on the surface—both involve reviewing existing research—they are fundamentally different in purpose, process, and academic value.
To begin, it's important to note that a systematic review is a specific type of literature review, one that follows a clearly defined and reproducible methodology. In contrast, a traditional literature review is more general, less structured, and often written to provide an overview of a topic or justify a research gap. Understanding the distinctions between these two is essential for students, researchers, and academics who aim to produce impactful and scientifically credible work.
Definitions and Overall Difference
Literature Review: A literature review is a narrative summary of existing research on a particular topic. It is often written at the beginning of a thesis or research paper to establish context, identify gaps, and justify the need for the current study.
Systematic Review: A systematic review is a rigorous, structured, and transparent method of identifying, appraising, and synthesizing all available evidence that answers a specific research question. It follows a pre-defined protocol and includes clear inclusion and exclusion criteria.
Overall, the key difference lies in methodology and purpose: systematic reviews aim to minimize bias and produce reliable evidence, while literature reviews are more interpretative and subjective in nature.
1. Publication Potential and Academic Prestige
One of the most telling differences between systematic reviews and literature reviews is how they're received in the academic publishing world.
Systematic reviews are widely accepted in high-impact, peer-reviewed journals due to their methodological rigor and contribution to evidence-based knowledge.
Literature reviews, on the other hand, are rarely accepted as standalone publications—unless they are published in low-impact or even predatory journals, which often lack proper editorial standards.
This makes systematic reviews far more valuable for researchers seeking to establish credibility and influence in their fields.
2. Scientific Rigor and Objectivity
A systematic review adheres to strict scientific standards. It typically includes:
A pre-registered protocol
Comprehensive search strategies across multiple databases
Transparent inclusion/exclusion criteria
Quality appraisal of included studies
Reproducibility and transparency
In contrast, literature reviews are often not scientifically rigorous. The selection of studies is usually left to the author’s discretion, making the process subjective and potentially biased. The absence of standardized methods means two authors could write entirely different reviews on the same topic.
3. Purpose and Research Intent
Literature reviews are often used to justify a research gap. They are commonly found in the introduction sections of theses, dissertations, or research proposals.
Systematic reviews aim to answer a specific research question. For example, "What are the barriers to PrEP uptake among MSM in the United States?" They are designed to inform practice, policy, and future research.
This fundamental difference in intent affects how each type of review is planned, executed, and applied.
4. Bias and Subjectivity
Bias in literature reviews is almost unavoidable. Since authors choose which studies to include, the result can be a selective and non-representative overview of the literature. This is particularly problematic when literature reviews are used to shape research decisions without a solid evidence base.
Systematic reviews, by contrast, minimize bias through transparency and replicability. Reviewers must document every step—from database search strategies to study selection and quality appraisal—allowing others to scrutinize or replicate the review.
5. Use in Evidence-Based Practice and Policy
Perhaps the most impactful difference lies in how each type of review is used.
Systematic reviews play a critical role in evidence-based medicine, public health policy, and clinical decision-making. They offer robust, high-quality summaries of evidence that guide practitioners and policymakers.
Literature reviews, however, do not hold the same weight in evidence hierarchies. Because of their lack of methodological rigor, they cannot be relied upon for informing policy or clinical guidelines.
6. Time, Resources, and Team Composition
Systematic reviews require significant time, resources, and often a team of reviewers. Due to the meticulous process involved—from protocol development to full-text screening and critical appraisal—they may take several months to complete.
In contrast, a literature review can often be completed by a single author in a few weeks, making it a preferred choice for early-stage research or assignments that don’t require rigorous analysis.
7. Tools and Software
Systematic reviews often involve tools such as:
Covidence, Rayyan, or RevMan for screening and data extraction
PRISMA guidelines for reporting
Risk of Bias tools for critical appraisal
Literature reviews, by contrast, typically don’t require such tools and are more narrative in style, resembling essays rather than data-driven syntheses.
Conclusion
While both systematic reviews and literature reviews aim to summarize existing knowledge, they do so in vastly different ways and with different goals in mind. A literature review is more subjective and often exploratory, whereas a systematic review is structured, reproducible, and designed to answer a specific research question.
For researchers seeking to produce high-impact, publication-ready work or influence evidence-based practice, the systematic review is the gold standard. Understanding the difference isn't just academic—it shapes the credibility, utility, and reception of your research.