What is a Systematic Literature Review: Definition, Tips & Examples


2nd July 2024

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A systematic literature review is a rigorous and structured approach to analysing research literature. It is essential for synthesising existing research, identifying gaps, and forming a robust foundation for new research. This article will define what a systematic literature review is, differentiate it from a traditional literature review, provide tips on how to conduct one, outline the structure, and present types and examples of systematic literature reviews.

What is a Systematic Literature Review?

A systematic literature review (SLR) is a methodical and comprehensive synthesis of research studies on a particular topic. It aims to identify, evaluate, and summarise the findings of all relevant individual studies, adhering to predefined criteria to ensure objectivity and transparency.

Key Characteristics:

  1. An SLR follows a clear, predefined protocol, including specific criteria for study selection and data extraction.
  2. It involves an exhaustive search of multiple databases and sources to identify all relevant studies.
  3. Each study is rigorously evaluated for quality and relevance.
  4. The findings from individual studies are systematically synthesised to provide a comprehensive overview of the evidence.

Systematic Review vs Literature Review

Understanding the difference between a systematic review and a literature review is crucial for researchers.

Literature Review:

  • Scope: Provides a general overview of research on a particular topic.
  • Structure: Less structured and may include a narrative synthesis.
  • Bias: More prone to subjective bias due to the lack of predefined criteria.

Systematic Review:

  • Scope: Focuses on answering a specific research question through a structured and rigorous approach.
  • Structure: Follows a predefined protocol with explicit criteria for study selection and data extraction.
  • Bias: Minimises bias through systematic and transparent methods.

How to Do a Systematic Literature Review

Conducting a systematic literature review involves several steps:

Step 1: Define the Research Question

Begin by clearly defining the research question. A well-defined question will guide the entire review process. Use frameworks like PICO (Population, Intervention, Comparison, Outcome) to structure your question.

Step 2: Develop a Protocol

Create a detailed protocol outlining the methodology for your review. This should include:

  • Inclusion and Exclusion Criteria: Define the criteria for selecting studies.
  • Search Strategy: Describe the databases and search terms you will use.
  • Data Extraction Methods: Specify how you will extract and manage data from the selected studies.
  • Quality Assessment: Outline the criteria for evaluating the quality of the studies.

Step 3: Conduct a Comprehensive Search

Perform a thorough search across multiple databases (e.g., PubMed, Scopus, Web of Science) and grey literature sources. Document your search process to ensure reproducibility.

Step 4: Screen and Select Studies

Screen the identified studies based on your inclusion and exclusion criteria. This process typically involves:

  • Title and Abstract Screening: Initial screening to exclude irrelevant studies.
  • Full-Text Screening: Detailed review of the remaining studies to confirm their relevance.

Step 5: Extract Data

Extract relevant data from the selected studies using a standardised data extraction form. Include details such as study design, sample size, outcomes measured, and key findings.

Step 6: Assess Study Quality

Critically appraise the quality of the included studies. Use tools like the Cochrane Risk of Bias Tool or the Joanna Briggs Institute Critical Appraisal Tools.

Step 7: Synthesise the Findings

Combine the findings from the individual studies. Depending on the nature of the data, this could involve:

  • Narrative Synthesis: Describing the findings qualitatively.
  • Meta-Analysis: Using statistical methods to combine quantitative data from multiple studies.

Step 8: Report the Results

Present your findings in a structured format. Follow guidelines such as PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) to ensure transparency and completeness.

Systematic Review Structure

The systematic review structure typically includes the following sections:

  1. Introduction:
    • Background information on the research topic.
    • Clear statement of the research question.
  2. Methods:
    • Detailed description of the search strategy.
    • Inclusion and exclusion criteria.
    • Data extraction and quality assessment methods.
  3. Results:
    • Summary of the study selection process (often presented as a PRISMA flow diagram).
    • Characteristics of the included studies.
    • Synthesis of the findings.
  4. Discussion:
    • Interpretation of the findings.
    • Comparison with existing literature.
    • Implications for practice and future research.
  5. Conclusion:
    • Summary of key findings.
    • Limitations of the review.
    • Recommendations for further research.
  6. References:
    • List of all sources cited in the review.

Types of Systematic Literature Review

There are various types of systematic literature reviews based on the research question and methodology:

Qualitative Systematic Review: Focuses on synthesising qualitative evidence from individual studies.

Quantitative Systematic Review: Combines quantitative data from multiple studies, often using meta-analysis.

Mixed-Methods Systematic Review: Integrates both qualitative and quantitative evidence.

Scoping Review: Maps the existing literature on a broad topic to identify gaps and inform future research.

Rapid Review: Conducted in a shorter timeframe with streamlined methods to provide timely evidence.

Systematic Review Example

Here is a simplified systematic review example to illustrate the process:

Title: The Effectiveness of Cognitive Behavioral Therapy for Anxiety Disorders in Adolescents

Introduction: Anxiety disorders are prevalent among adolescents and have significant impacts on their well-being. Cognitive Behavioral Therapy (CBT) is a common intervention, but its effectiveness in this population needs to be systematically evaluated.


  • Search Strategy: Searched PubMed, Scopus, and PsycINFO using terms such as “CBT,” “anxiety disorders,” and “adolescents.”
  • Inclusion Criteria: Randomised controlled trials (RCTs) assessing CBT for anxiety in adolescents.
  • Data Extraction: Extracted data on study design, sample size, intervention details, and outcomes.


  • Study Selection: 15 RCTs met the inclusion criteria.
  • Quality Assessment: Most studies had low risk of bias.
  • Synthesis: Meta-analysis showed a significant reduction in anxiety symptoms following CBT compared to control conditions.

Discussion: CBT is an effective intervention for reducing anxiety symptoms in adolescents. Future research should explore long-term outcomes and mechanisms of change.

Conclusion: CBT shows promise for treating anxiety disorders in adolescents, with significant short-term benefits. Further studies are needed to confirm these findings and explore additional factors.


A systematic literature review is a rigorous method for synthesising research evidence to answer a specific question. By following a structured approach, developing a clear protocol, and critically appraising and synthesising the findings, researchers can provide valuable insights into their field of study. Understanding systematic review vs literature review, knowing how to do a systematic literature review, and recognising the various types of systematic literature reviews are essential skills for conducting high-quality research. With careful planning and execution, a systematic review can significantly contribute to academic knowledge and practice.

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