What is a Systematic Literature Review? How to Conduct a Systematic Review of the Literature

What is a Systematic Literature Review?

A systematic literature review is a research method that allows researchers to systematically search, evaluate, and synthesize existing research on a specific topic or research question. This process involves a clear, structured approach to gather all relevant studies, analyze them, and draw evidence-based conclusions.

What is a Systematic Literature Review and How is it Different from Literature Reviews?

• Definition of a Systematic Literature Review: A systematic literature review is a comprehensive, structured, and methodical process for identifying, evaluating, and synthesizing the results of all relevant studies on a particular research question.
• Difference from Traditional Literature Reviews:
  • A traditional literature review often involves a more general and subjective summary of studies, whereas a systematic review strictly follows a predefined protocol to minimize bias.
  • Systematic reviews are evidence-based and involve a rigorous systematic search for all available evidence, including grey literature, to ensure no relevant study is overlooked.
  • Unlike traditional reviews, systematic reviews focus on data extraction from primary studies, which are then synthesized to answer the formulated research questions.

Systematic Review as a Research Methodology: A Step-by-Step Guide

• Step 1: Formulate Research Questions:
  A clear research question must be formulated. This is the first step in understanding what is a systematic literature review. These questions guide the entire process and ensure a focused search of relevant studies.
• Step 2: Develop a Protocol:
  A review protocol outlines the specific methods and criteria used for the review. It includes the types of research, inclusion and exclusion criteria, and the approach to synthesize data from multiple studies.
• Step 3: Conduct a Systematic Search:
  A systematic search of multiple databases is essential to locate all relevant studies. Researchers use library guides, databases, and other resources to ensure that no important information is missed. This search often includes grey literature, which includes unpublished or hard-to-find studies.
• Step 4: Apply Inclusion and Exclusion Criteria:
  Researchers apply inclusion and exclusion criteria to filter studies that are relevant to the research question. This helps maintain focus on the studies that are of the highest quality and most relevant to the research topic.
• Step 5: Data Extraction:
  After the relevant studies are identified, researchers extract data from the studies according to predefined criteria. This could include study design, sample size, results, and other key variables.
• Step 6: Synthesize the Evidence:
  Once data is extracted, the results from the studies are combined and analyzed to form evidence syntheses. In some cases, researchers may use meta-analysis to statistically synthesize data across studies.
• Step 7: Report the Results:
  The final results are reported using the preferred reporting items for systematic reviews (PRISMA). This checklist ensures the review is transparent, reproducible, and of high quality.

Common Challenges in Systematic Literature Reviews

• Challenge 1: Time Consumption:
  The process of conducting a systematic review can be very time-consuming. It involves comprehensive searching, screening, data extraction, and synthesis of large volumes of studies. Researchers often spend several months or even years to complete a systematic review.
• Challenge 2: Risk of Bias:
  Even with a systematic approach, there is always a risk of bias in systematic reviews and meta-analyses. Ensuring a transparent and replicable methodology, as well as using a rigorous checklist, can help reduce bias.
• Challenge 3: Lack of Standardized Reporting:
  The absence of standardized reporting items for systematic reviews may lead to inconsistencies in how the results are reported, making it harder to compare different studies or draw conclusive findings.
• Challenge 4: Data Availability:
  In some cases, access to the necessary studies or data may be limited, especially when it comes to grey literature or unpublished research. This can impact the comprehensiveness of the review process.
• Challenge 5: Complex Data Synthesis:
  Synthesizing data from multiple studies, especially when the studies differ in methodology or findings, can be complex. Researchers need to ensure they apply systematic review methods that are appropriate for synthesizing diverse types of research data.

This section provides an overview of what is a systematic literature review, how it differs from traditional literature reviews, and the steps involved in conducting a rigorous review. The systematic review process is crucial for producing evidence-based conclusions and ensuring that research is comprehensive, transparent, and free from bias.

How to Conduct a Systematic Literature Review Effectively

Conducting a systematic literature review is a methodical process designed to gather and assess all available research on a specific topic. To effectively conduct and report on a systematic review, you need to follow a structured process that minimizes bias, maximizes transparency, and ensures the review is comprehensive. Here’s how you can conduct a systematic literature review step-by-step:

Defining Your Research Question: A Critical First Step

• Formulate a Clear Research Question:
  • Understanding what is a systematic literature review begins with the development of a focused research question. This question defines the scope of the review and guides the entire process.
  • The review question should be specific, measurable, and feasible to answer with available research.
  • Use frameworks such as the PICO (Population, Intervention, Comparison, Outcome) or SPICE (Setting, Perspective, Intervention, Comparison, Evaluation) to structure your question.
• Purpose of the Research Question:
  • The research question ensures you are reviewing relevant research studies that answer a clear, defined query.
  • A systematic review requires the formulation of a question that can guide the systematic review process, focusing on both the quantity and quality of literature.
• Types of Review Questions:
  • Review questions in systematic reviews typically focus on comparing interventions, identifying outcomes, or understanding research evidence.
  • Formulating questions based on the type of literature review you are conducting (e.g., experimental studies, observational studies).

Developing a Comprehensive Search Strategy for Systematic Reviews

• Conduct a Systematic Search for Relevant Literature:
  • Understanding what is a systematic literature review involves systematically searching databases like Web of Science, PubMed, or University library systems.
  • A systematic review requires using systematic review methods to search for both primary research and grey literature.
• Incorporate Review Types and Protocol:
  • Each type of literature review has its own protocols. A systematic review uses a protocol for a systematic review to guide the search strategy, including inclusion and exclusion criteria.
  • A systematic search should focus on finding all relevant literature, both published and unpublished, using comprehensive search terms.
• Use Systematic Frameworks:
  • The search strategy should be informed by a typology of reviews framework, ensuring that only the most relevant research is included.
  • This structured approach helps you capture all necessary studies while reducing the risk of bias in your findings.

Evaluating and Selecting Studies: Key Considerations for Systematic Reviews

• Critically Appraise Existing Research:
  • As part of conducting a systematic literature review, you need to assess the quality of each research study included in your review.
  • Critical appraisal involves evaluating the validity, reliability, and generalizability of the findings.
  • Use checklists and tools like PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) to evaluate the quality of studies.
• Assess Relevance and Quality:
  • Evaluating and selecting studies means assessing both the relevance of the study to the review question and its methodological quality.
  • Studies should be selected based on clearly defined inclusion and exclusion criteria, and only those that meet high standards of evidence should be included.
• Reporting and Synthesizing Results:
  • The final review report should summarize the research findings, ensuring the systematic review clearly outlines research gaps and new research directions.
  • It’s essential to synthesize findings from different studies in a transparent manner, discussing the strengths and weaknesses of each.

This section has explained what is a systematic literature review and provided the steps necessary to effectively conduct a systematic review. Starting with formulating a review question, developing a comprehensive search strategy, and evaluating the quality of the studies, researchers can ensure that the review is as robust and unbiased as possible. By following these steps, you can conduct systematic literature reviews that are clear, evidence-based, and thorough, providing valuable insights for your research community.

Writing and Presenting a Systematic Literature Review

Writing and presenting a systematic literature review is a crucial process for synthesizing existing research and providing evidence-based conclusions. Here are the steps to help guide you through the structure and presentation of a systematic review, ensuring that it’s clear, thorough, and impactful.

Structuring Systematic Review Methodology: Key Sections and Format

• Introduction:
  • Clearly define what is a systematic literature review and explain the scope of your review.
  • State the review question and the objective of the systematic review.
  • Provide a brief overview of types of systematic reviews and why this methodology is the best fit for your research.
• Methods Section:
  • Outline the systematic review methodology used to search, evaluate, and synthesize studies.
  • Include details on how you formulated your research plan, the databases searched, and the inclusion/exclusion criteria used to select studies.
  • Describe how you conducted systematic searches, using tools like research protocols and systematic way of organizing studies.
  • Reference relevant items for reporting in systematic reviews, such as PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses).
• Results Section:
  • Present the research literature found during your review.
  • Use charts, tables, or graphs to clearly illustrate key findings, trends, and patterns identified in the research studies.
  • Group studies according to review types and associated outcomes, making sure to follow a consistent format to organize the data.
• Discussion Section:
  • Synthesize the research evidence and compare findings across studies.
  • Discuss limitations of the studies reviewed, potential sources of bias, and implications for future research.
  • Highlight any gaps in the current literature and explain why they are important for future studies.

Presenting Your Research Data and Findings Effectively

• Clear Data Presentation:
  • To help readers understand your findings, ensure that you present your research data in an easy-to-read format.
  • Use clear reporting in systematic reviews, focusing on transparency and accuracy.
  • Incorporate relevant research literature, emphasizing key trends and conclusions from your data synthesis.
• Using Visual Aids:
  • Present data using tables, figures, or flowcharts to show the relationship between studies or to summarize key data points.
  • Make sure visual aids align with your systematic review methodology and improve comprehension of your findings.
• Discussion of Data:
  • After presenting data, provide a systematic review of the evidence to explain what the data means in context.
  • Discuss any inconsistencies between studies and how they may affect the reliability of the findings.

Writing a Strong Conclusion and Implications for Future Research

• Conclude with a Summary:
  • In the conclusion of your systematic review, restate the research question and summarize the major findings.
  • Highlight the significance of the systematic literature review and its contributions to the field.
• Implications for Future Research:
  • Discuss the implications for future research based on gaps identified in the current literature. For example, mention the need for more studies in specific areas, or suggest new research protocols based on findings.
  • Indicate how future research could address unresolved questions or apply findings in clinical or practical settings, especially if systematic reviews in clinical settings are relevant to your field.
• Strengths and Limitations:
  • Acknowledge the strengths of your review, such as the comprehensive search strategy and the transparency of your methodology.
  • Discuss any limitations, including potential bias or the availability of research literature in your field, and how these limitations might affect the interpretation of your findings.
• Future Directions:
  • Based on the systematic review you’ve conducted, propose future research questions or areas where literature reviews provide additional insights.
  • Explain how systematic reviews ask critical questions that will help guide future academic inquiries and inform real-world applications.

By following these steps, you will have a clear and effective structure for writing a systematic literature review that adheres to standard reporting practices. It will also provide a comprehensive analysis of the research literature, effectively synthesizing data while highlighting gaps and opportunities for future studies. A well-structured review is an essential contribution to the academic community and will help others understand what is a systematic literature review in practice.