Systematic Literature Review Guide for Researchers

Systematic Literature Review Guide for Researchers

A systematic literature review (SLR) forms the backbone of evidence-based research across disciplines. This systematic literature review guide walks you through each essential step of the process. Whether you're a seasoned researcher or a graduate student tackling your first major project, understanding the structured approach to reviewing literature systematically will elevate your research quality.

Planning & Protocol Development

Planning lays the foundation for a successful systematic literature review. This critical first phase determines the direction and scope of your entire project.

Defining Scope & Research Questions

Every strong systematic literature review begins with clear, focused research questions. The PICO framework offers an excellent structure:

  • Population: Who or what is being studied?
  • Intervention: What action or treatment is being investigated?
  • Comparison: What is the alternative to the intervention?
  • Outcome: What results are you measuring?

Your research questions should be specific enough to guide your search strategy but broad enough to capture relevant literature. Writing them down helps maintain focus throughout your review process.

Avoid scope creep by setting firm boundaries. Determine your time frame, study types, and languages at the outset. A narrower scope often produces more meaningful results than an overly ambitious one.

Consider consulting subject matter experts during this phase. Their insights can help refine your questions and identify potential blind spots in your approach.

Registering Protocols

Registration brings transparency and credibility to your systematic literature review. PROSPERO, an international database for systematic review protocols, allows you to register your review plan before conducting searches.

The benefits of protocol registration include:

  • Reducing duplication of research efforts
  • Preventing selective reporting bias
  • Establishing methodological rigor
  • Creating accountability for the research team

Your protocol should outline your research questions, inclusion criteria, search strategies, and analysis methods. Think of it as a roadmap that keeps your review on track.

Many journals now require protocol registration before submission. Even if not required, the practice demonstrates methodological thoroughness to reviewers and readers alike.

Search Strategy & Screening

A comprehensive search strategy captures all relevant literature while minimizing irrelevant results. This balance requires careful planning and documentation.

Database Selection

Choosing the right databases significantly impacts your systematic literature review quality. Different fields have preferred databases:

  • Medical Sciences: PubMed, Cochrane Library, CINAHL
  • Psychology: PsycINFO, PsycARTICLES
  • Business/Management: Business Source Complete, ABI/INFORM
  • Social Sciences: Web of Science, Scopus, JSTOR
  • Education: ERIC, Education Source

Don't limit yourself to just one database. Cross-database searching catches studies that might be missed in a single source. Google Scholar can supplement traditional databases but shouldn't replace them.

Work with a librarian to develop sophisticated search strings. Their expertise can help you leverage advanced search operators and controlled vocabulary terms specific to each database.

Document every search precisely—including database names, search dates, terms used, and filters applied. This documentation enables others to replicate your search process.

Inclusion/Exclusion Criteria

Clear criteria form the backbone of your screening process. Develop these before beginning your search to avoid bias in study selection.

Common inclusion criteria might specify:

  • Publication timeframe (e.g., studies from 2010-2023)
  • Study designs (randomized controlled trials, cohort studies)
  • Population characteristics (adults with Type 2 diabetes)
  • Language restrictions (English and Spanish only)

Exclusion criteria might remove:

  • Conference abstracts without full papers
  • Studies with inadequate methodological quality
  • Sample sizes below a predefined threshold
  • Duplicate reports of the same study

Test your criteria on a sample of studies before full implementation. This piloting process helps identify ambiguities that need clarification.

Use a multi-reviewer approach during screening. Having at least two independent reviewers reduces selection bias and human error. Establish a process for resolving disagreements between reviewers.

PRISMA Flow Diagram

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram visually documents your systematic literature review process. This transparent reporting shows readers exactly how you arrived at your final study selection.

The diagram tracks four main phases:

  • Identification: Number of records identified through database searching
  • Screening: Records after duplicates removed and initial screening
  • Eligibility: Full-text articles assessed for eligibility
  • Included: Final studies included in your review

Creating this diagram requires meticulous record-keeping throughout your search and screening process. Note the number of studies excluded at each stage and the reasons for exclusion.

The latest PRISMA guidelines (2020) offer updated templates and guidance for creating these diagrams. Following these standards enhances the credibility and reproducibility of your systematic literature review.

Data Extraction & Synthesis

After identifying relevant studies, you'll need systematic methods to extract and analyze their findings. This phase transforms individual study data into meaningful conclusions.

Creating Extraction Forms

Data extraction forms ensure consistent information collection across all studies. Design these forms before beginning extraction to avoid missing crucial details.

A comprehensive extraction form typically captures:

  • Study characteristics (authors, publication year, country)
  • Methodological details (design, sample size, duration)
  • Participant information (demographics, inclusion criteria)
  • Intervention specifics (type, duration, frequency)
  • Outcome measures and results
  • Quality assessment indicators

Pilot your extraction form on several studies before full implementation. This testing reveals whether the form captures all necessary information or needs refinement.

Electronic forms offer advantages over paper, including direct data entry into analysis software. Tools like Covidence, Rayyan, or even customized spreadsheets can streamline this process.

Assign multiple reviewers to extract data independently. Then compare their results to identify and resolve discrepancies. This double-checking improves accuracy and reliability in your systematic literature review.

Narrative vs. Quantitative Synthesis

Your synthesis approach depends on your research questions and the nature of your collected data. Most systematic literature reviews use either narrative synthesis, quantitative methods, or both.

Narrative synthesis organizes findings thematically when studies are too diverse for statistical combination. This approach:

  • Identifies patterns across studies
  • Groups findings under conceptual headings
  • Explores relationships between studies
  • Assesses the robustness of evidence

Quantitative synthesis (meta-analysis) statistically combines results from similar studies. This method:

  • Increases statistical power
  • Improves estimate precision
  • Quantifies inconsistencies across studies
  • Identifies publication bias

Mixed-methods reviews incorporate both approaches. You might quantitatively analyze some outcomes while narratively synthesizing others that resist statistical combination.

Regardless of your synthesis method, maintain transparency. Clearly document your analysis decisions and acknowledge limitations in your systematic literature review guide.

Writing & Reporting

Clear, structured reporting distinguishes exceptional systematic literature reviews from mediocre ones. This section guides you through effective presentation of your findings.

Structuring Results & Discussion

Your results section should present findings in a logical, unbiased manner. Begin with descriptive statistics about included studies before diving into thematic or statistical analyses.

Consider organizing results by:

  • Research question
  • Outcome measures
  • Chronological development
  • Methodological approach

Use tables and figures to present complex information concisely. Visual representations often communicate patterns more effectively than text alone.

In your discussion section:

  • Summarize principal findings
  • Compare results with existing literature
  • Explain unexpected outcomes
  • Address strengths and limitations
  • Discuss implications for practice and policy

Avoid overstating conclusions. Acknowledge gaps in the literature and areas where evidence remains inconclusive.

Throughout your systematic literature review, maintain a balance between detail and clarity. Provide enough information for reproducibility without overwhelming readers with excessive technical details.

Adhering to PRISMA Checklist

The PRISMA checklist serves as the gold standard for systematic literature review reporting. Following these guidelines ensures comprehensive coverage of all essential elements.

The checklist contains 27 items across seven sections:

  • Title and Abstract
  • Introduction
  • Methods
  • Results
  • Discussion
  • Funding
  • Other information

Using this systematic framework improves transparency and helps readers evaluate your review's validity. Many journals now require PRISMA compliance for submission.

Beyond the main checklist, specialized extensions exist for different review types. These include PRISMA-ScR for scoping reviews, PRISMA-P for protocols, and PRISMA-NMA for network meta-analyses.

Complete the checklist as you write, rather than retrospectively. This approach ensures you address all elements appropriately in your systematic literature review guide.

Conclusion & Resources

Conducting a systematic literature review requires methodical planning, rigorous execution, and transparent reporting. While demanding, the process generates valuable contributions to your field's knowledge base.

Remember that systematic literature reviews represent living documents. As new evidence emerges, reviews may require updating to maintain relevance. Consider establishing timelines for revisiting your review in rapidly evolving fields.

For practical assistance, Supremessay.com offers comprehensive templates that guide you through each step of the systematic literature review process. These resources save time while ensuring methodological rigor.

By following this systematic literature review guide, you'll produce work that meets the highest standards of evidence synthesis—work that informs practice, guides policy, and advances knowledge in your discipline.

Frequently Asked Questions

What's the PRISMA checklist?

The PRISMA checklist contains 27 essential items for transparent reporting of systematic reviews. It covers everything from title formulation to funding disclosure. Researchers use this checklist to ensure they've addressed all critical elements in their reviews. Journal editors and reviewers often require PRISMA compliance before publication consideration. The latest version (PRISMA 2020) incorporates updates based on methodological advancements in systematic review practices.

How many studies are enough for a systematic literature review?

No fixed number determines adequacy for a systematic literature review. Some reviews include hundreds of studies, while others may include fewer than ten. The appropriate number depends on your research question's scope and available evidence. More important than quantity is your search's comprehensiveness and transparency. A review with few studies resulting from rigorous searching still provides valuable insights, especially in emerging fields. Quality assessment becomes particularly important when working with smaller study sets.

Can narrative reviews qualify as systematic literature reviews?

No, narrative reviews cannot qualify as systematic literature reviews. The fundamental difference lies in methodology. Systematic reviews follow transparent, reproducible protocols with comprehensive search strategies and explicit inclusion criteria. Narrative reviews typically lack these rigorous methods, allowing more subjective study selection. While both have value, systematic reviews sit higher in the evidence hierarchy due to their reduced bias risk. Some reviews combine elements of both approaches, creating "systematized" reviews that incorporate some systematic methods without full implementation.

Systematic Literature Review Guide for Researchers

A systematic literature review (SLR) forms the backbone of evidence-based research across disciplines. This systematic literature review guide walks you through each essential step of the process. Whether you're a seasoned researcher or a graduate student tackling your first major project, understanding the structured approach to reviewing literature systematically will elevate your research quality.

Planning & Protocol Development

Planning lays the foundation for a successful systematic literature review. This critical first phase determines the direction and scope of your entire project.

Defining Scope & Research Questions

Every strong systematic literature review begins with clear, focused research questions. The PICO framework offers an excellent structure:

  • Population: Who or what is being studied?
  • Intervention: What action or treatment is being investigated?
  • Comparison: What is the alternative to the intervention?
  • Outcome: What results are you measuring?

Your research questions should be specific enough to guide your search strategy but broad enough to capture relevant literature. Writing them down helps maintain focus throughout your review process.

Avoid scope creep by setting firm boundaries. Determine your time frame, study types, and languages at the outset. A narrower scope often produces more meaningful results than an overly ambitious one.

Consider consulting subject matter experts during this phase. Their insights can help refine your questions and identify potential blind spots in your approach.

Registering Protocols

Registration brings transparency and credibility to your systematic literature review. PROSPERO, an international database for systematic review protocols, allows you to register your review plan before conducting searches.

The benefits of protocol registration include:

  • Reducing duplication of research efforts
  • Preventing selective reporting bias
  • Establishing methodological rigor
  • Creating accountability for the research team

Your protocol should outline your research questions, inclusion criteria, search strategies, and analysis methods. Think of it as a roadmap that keeps your review on track.

Many journals now require protocol registration before submission. Even if not required, the practice demonstrates methodological thoroughness to reviewers and readers alike.

Search Strategy & Screening

A comprehensive search strategy captures all relevant literature while minimizing irrelevant results. This balance requires careful planning and documentation.

Database Selection

Choosing the right databases significantly impacts your systematic literature review quality. Different fields have preferred databases:

  • Medical Sciences: PubMed, Cochrane Library, CINAHL
  • Psychology: PsycINFO, PsycARTICLES
  • Business/Management: Business Source Complete, ABI/INFORM
  • Social Sciences: Web of Science, Scopus, JSTOR
  • Education: ERIC, Education Source

Don't limit yourself to just one database. Cross-database searching catches studies that might be missed in a single source. Google Scholar can supplement traditional databases but shouldn't replace them.

Work with a librarian to develop sophisticated search strings. Their expertise can help you leverage advanced search operators and controlled vocabulary terms specific to each database.

Document every search precisely—including database names, search dates, terms used, and filters applied. This documentation enables others to replicate your search process.

Inclusion/Exclusion Criteria

Clear criteria form the backbone of your screening process. Develop these before beginning your search to avoid bias in study selection.

Common inclusion criteria might specify:

  • Publication timeframe (e.g., studies from 2010-2023)
  • Study designs (randomized controlled trials, cohort studies)
  • Population characteristics (adults with Type 2 diabetes)
  • Language restrictions (English and Spanish only)

Exclusion criteria might remove:

  • Conference abstracts without full papers
  • Studies with inadequate methodological quality
  • Sample sizes below a predefined threshold
  • Duplicate reports of the same study

Test your criteria on a sample of studies before full implementation. This piloting process helps identify ambiguities that need clarification.

Use a multi-reviewer approach during screening. Having at least two independent reviewers reduces selection bias and human error. Establish a process for resolving disagreements between reviewers.

PRISMA Flow Diagram

The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram visually documents your systematic literature review process. This transparent reporting shows readers exactly how you arrived at your final study selection.

The diagram tracks four main phases:

  • Identification: Number of records identified through database searching
  • Screening: Records after duplicates removed and initial screening
  • Eligibility: Full-text articles assessed for eligibility
  • Included: Final studies included in your review

Creating this diagram requires meticulous record-keeping throughout your search and screening process. Note the number of studies excluded at each stage and the reasons for exclusion.

The latest PRISMA guidelines (2020) offer updated templates and guidance for creating these diagrams. Following these standards enhances the credibility and reproducibility of your systematic literature review.

Data Extraction & Synthesis

After identifying relevant studies, you'll need systematic methods to extract and analyze their findings. This phase transforms individual study data into meaningful conclusions.

Creating Extraction Forms

Data extraction forms ensure consistent information collection across all studies. Design these forms before beginning extraction to avoid missing crucial details.

A comprehensive extraction form typically captures:

  • Study characteristics (authors, publication year, country)
  • Methodological details (design, sample size, duration)
  • Participant information (demographics, inclusion criteria)
  • Intervention specifics (type, duration, frequency)
  • Outcome measures and results
  • Quality assessment indicators

Pilot your extraction form on several studies before full implementation. This testing reveals whether the form captures all necessary information or needs refinement.

Electronic forms offer advantages over paper, including direct data entry into analysis software. Tools like Covidence, Rayyan, or even customized spreadsheets can streamline this process.

Assign multiple reviewers to extract data independently. Then compare their results to identify and resolve discrepancies. This double-checking improves accuracy and reliability in your systematic literature review.

Narrative vs. Quantitative Synthesis

Your synthesis approach depends on your research questions and the nature of your collected data. Most systematic literature reviews use either narrative synthesis, quantitative methods, or both.

Narrative synthesis organizes findings thematically when studies are too diverse for statistical combination. This approach:

  • Identifies patterns across studies
  • Groups findings under conceptual headings
  • Explores relationships between studies
  • Assesses the robustness of evidence

Quantitative synthesis (meta-analysis) statistically combines results from similar studies. This method:

  • Increases statistical power
  • Improves estimate precision
  • Quantifies inconsistencies across studies
  • Identifies publication bias

Mixed-methods reviews incorporate both approaches. You might quantitatively analyze some outcomes while narratively synthesizing others that resist statistical combination.

Regardless of your synthesis method, maintain transparency. Clearly document your analysis decisions and acknowledge limitations in your systematic literature review guide.

Writing & Reporting

Clear, structured reporting distinguishes exceptional systematic literature reviews from mediocre ones. This section guides you through effective presentation of your findings.

Structuring Results & Discussion

Your results section should present findings in a logical, unbiased manner. Begin with descriptive statistics about included studies before diving into thematic or statistical analyses.

Consider organizing results by:

  • Research question
  • Outcome measures
  • Chronological development
  • Methodological approach

Use tables and figures to present complex information concisely. Visual representations often communicate patterns more effectively than text alone.

In your discussion section:

  • Summarize principal findings
  • Compare results with existing literature
  • Explain unexpected outcomes
  • Address strengths and limitations
  • Discuss implications for practice and policy

Avoid overstating conclusions. Acknowledge gaps in the literature and areas where evidence remains inconclusive.

Throughout your systematic literature review, maintain a balance between detail and clarity. Provide enough information for reproducibility without overwhelming readers with excessive technical details.

Adhering to PRISMA Checklist

The PRISMA checklist serves as the gold standard for systematic literature review reporting. Following these guidelines ensures comprehensive coverage of all essential elements.

The checklist contains 27 items across seven sections:

  • Title and Abstract
  • Introduction
  • Methods
  • Results
  • Discussion
  • Funding
  • Other information

Using this systematic framework improves transparency and helps readers evaluate your review's validity. Many journals now require PRISMA compliance for submission.

Beyond the main checklist, specialized extensions exist for different review types. These include PRISMA-ScR for scoping reviews, PRISMA-P for protocols, and PRISMA-NMA for network meta-analyses.

Complete the checklist as you write, rather than retrospectively. This approach ensures you address all elements appropriately in your systematic literature review guide.

Conclusion & Resources

Conducting a systematic literature review requires methodical planning, rigorous execution, and transparent reporting. While demanding, the process generates valuable contributions to your field's knowledge base.

Remember that systematic literature reviews represent living documents. As new evidence emerges, reviews may require updating to maintain relevance. Consider establishing timelines for revisiting your review in rapidly evolving fields.

For practical assistance, Supremessay.com offers comprehensive templates that guide you through each step of the systematic literature review process. These resources save time while ensuring methodological rigor.

By following this systematic literature review guide, you'll produce work that meets the highest standards of evidence synthesis—work that informs practice, guides policy, and advances knowledge in your discipline.

Frequently Asked Questions

What's the PRISMA checklist?

The PRISMA checklist contains 27 essential items for transparent reporting of systematic reviews. It covers everything from title formulation to funding disclosure. Researchers use this checklist to ensure they've addressed all critical elements in their reviews. Journal editors and reviewers often require PRISMA compliance before publication consideration. The latest version (PRISMA 2020) incorporates updates based on methodological advancements in systematic review practices.

How many studies are enough for a systematic literature review?

No fixed number determines adequacy for a systematic literature review. Some reviews include hundreds of studies, while others may include fewer than ten. The appropriate number depends on your research question's scope and available evidence. More important than quantity is your search's comprehensiveness and transparency. A review with few studies resulting from rigorous searching still provides valuable insights, especially in emerging fields. Quality assessment becomes particularly important when working with smaller study sets.

Can narrative reviews qualify as systematic literature reviews?

No, narrative reviews cannot qualify as systematic literature reviews. The fundamental difference lies in methodology. Systematic reviews follow transparent, reproducible protocols with comprehensive search strategies and explicit inclusion criteria. Narrative reviews typically lack these rigorous methods, allowing more subjective study selection. While both have value, systematic reviews sit higher in the evidence hierarchy due to their reduced bias risk. Some reviews combine elements of both approaches, creating "systematized" reviews that incorporate some systematic methods without full implementation.