How to Conduct a Scoping Review
By Dr. Zubair Khalid, DVM, MS, PhD ·
Quick Answer
- A scoping review maps the breadth of evidence on a broad topic using a structured protocol, systematic search, and transparent reporting.
- Start by registering a protocol and selecting a reporting guideline from the EQUATOR Network before you begin searching.
- Scoping reviews describe evidence gaps and concepts, but they do not assess the quality of included studies or answer questions about intervention effectiveness.
What a Scoping Review Is and When to Use One
A scoping review is a structured method for mapping the existing literature on a broad topic. It answers questions like "What is known about X?" or "What types of evidence exist for Y?" instead of "Does intervention A work better than intervention B?" This distinction matters for researchers, students, and laboratory staff who need to decide which review method fits their question.
Scoping reviews are appropriate when you want to identify the range of research activity, clarify key concepts, examine how research is conducted on a topic, or identify gaps in the evidence base. They are also useful when a topic has not been reviewed comprehensively or when the literature is complex and heterogeneous.
A systematic review, by contrast, typically answers a focused question about effectiveness and includes a quality appraisal of included studies. A scoping review does not usually include a formal quality assessment. This is a deliberate design choice, not an oversight. The goal is breadth and coverage, not synthesis of effect estimates.
The National Library of Medicine provides access to authoritative biomedical books and research-method references that explain the distinctions between review types and the steps involved in conducting them. Consulting these resources early helps you align your methods with established practice.
Core Principles of Scoping Review Methodology
Scoping reviews rest on several core principles that guide every stage of the process. These principles ensure that the review is transparent, reproducible, and useful to readers.
Transparency and Reproducibility
A scoping review must be conducted in a way that another researcher could replicate. This means documenting every decision, from the research question to the search strategy to the data extraction process. Transparency also means reporting what you did and why you did it, including deviations from your original protocol.
Structured Approach
Scoping reviews follow a structured framework. The Joanna Briggs Institute methodology, which is described in detail in resources available through the National Library of Medicine, outlines specific stages for conducting a scoping review. These stages include identifying the research question, identifying relevant studies, selecting studies, charting the data, and collating, summarizing, and reporting the results.
Iterative Nature
Unlike systematic reviews, scoping reviews are often iterative. You may refine your search strategy as you become more familiar with the literature. You may also adjust your inclusion criteria based on what you find. This flexibility is a feature of the method, but it must be documented so readers understand how the final review took shape.
Reporting Standards
Transparent reporting is a core principle of ethical research. The EQUATOR Network maintains a comprehensive collection of reporting guidelines for health research, including the PRISMA-ScR guideline for scoping reviews. Selecting the appropriate reporting guideline before you begin helps ensure that your final manuscript includes all necessary elements.
The Joanna Briggs Institute Framework
The Joanna Briggs Institute (JBI) framework is one of the most widely used approaches for conducting scoping reviews. It provides a step-by-step workflow that researchers can follow from protocol development to final reporting.
Stage 1: Identify the Research Question
Your research question should be broad enough to capture the range of evidence on your topic but focused enough to be answerable. The JBI framework recommends using the PCC framework to structure your question:
- Population: Who or what is being studied?
- Concept: What is the focus of the review?
- Context: What setting or circumstances are relevant?
For example, a scoping review in ecology might ask: "What is known about the use of camera traps to monitor mammalian biodiversity in agricultural landscapes?" Here, the population is mammals, the concept is camera trap monitoring, and the context is agricultural landscapes.
Stage 2: Identify Relevant Studies
This stage involves developing a comprehensive search strategy. You will typically search multiple databases, review reference lists of included studies, and consult experts in the field. The search strategy should be documented in enough detail that it can be replicated.
Stage 3: Study Selection
Study selection involves screening titles and abstracts against your inclusion criteria, then reviewing full texts of potentially relevant studies. Two reviewers should independently screen studies to reduce bias. Disagreements are resolved through discussion or by consulting a third reviewer.
Stage 4: Charting the Data
Charting is the scoping review equivalent of data extraction. You will develop a data charting form that captures key information from each included study. Common charting items include author, year, country, study design, population, concept, context, and key findings. The form should be pilot tested on several studies and refined as needed.
Stage 5: Collating, Summarizing, and Reporting Results
The final stage involves organizing the charted data into a coherent summary. This typically includes a narrative summary, tables, and figures that describe the range of evidence. The results should be presented in a way that answers your research question and highlights gaps in the literature.
Developing a Protocol Before You Search
A protocol is a written plan that describes the rationale, objectives, and methods for your scoping review. Developing a protocol before you begin searching is a critical step for several reasons.
Why a Protocol Matters
A protocol increases transparency and reduces the risk of bias. It forces you to think through your methods in advance and provides a record of your decisions. If you deviate from your protocol, you can document the deviation and explain why it was necessary.
Protocol Registration
Many journals and funders expect scoping review protocols to be registered in a public registry. Registration makes your review visible to others and helps avoid duplication of effort. The National Institutes of Health provides guidance on grant policy and application processes, and some funding opportunities require protocol registration as part of the application.
What to Include in a Protocol
A scoping review protocol should include:
- The research question and objectives
- The PCC framework elements
- The inclusion criteria
- The search strategy, including databases and search terms
- The study selection process
- The data charting approach
- The planned methods for summarizing and reporting results
Protocol Updates
Your protocol is a living document. As you conduct the review, you may find that your initial plans need adjustment. Document any changes and explain the rationale. This is consistent with the iterative nature of scoping reviews and demonstrates methodological rigor.
Building a Systematic Search Strategy
The search strategy is the backbone of your scoping review. A poorly designed search will miss relevant studies, while an overly broad search will produce an unmanageable number of records.
Selecting Databases
Choose databases that are relevant to your topic. For biomedical topics, this might include PubMed, Embase, and CINAHL. For ecology topics, you might search Web of Science, Scopus, and Agricola. The National Library of Medicine provides access to resources that can help you identify appropriate databases for your field.
Developing Search Terms
Start by identifying key concepts from your research question. For each concept, list synonyms, related terms, and variant spellings. Combine these terms using Boolean operators. Use database-specific syntax, such as MeSH terms in PubMed, to improve precision.
Documenting the Search
Record the date of each search, the database searched, the search string used, and the number of results retrieved. This documentation is essential for the reporting stage and for reproducibility.
Managing Records
Use reference management software to store and organize your search results. Remove duplicates and maintain a record of the screening process. The National Library of Medicine resources include guidance on managing bibliographic data.
Study Selection and Screening
Study selection is a multi-step process that moves from broad screening to final inclusion.
Title and Abstract Screening
Screen titles and abstracts against your inclusion criteria. Studies that clearly do not meet the criteria are excluded. Studies that might meet the criteria proceed to full-text review. Two reviewers should screen independently, and disagreements should be resolved through discussion.
Full-Text Review
Retrieve full texts of potentially relevant studies and assess them against your inclusion criteria. Document the reasons for exclusion at this stage. A PRISMA flow diagram is commonly used to report the number of records identified, screened, included, and excluded at each stage.
Inclusion Criteria
Your inclusion criteria should be specific enough to guide screening decisions. They should be based on the PCC framework and may include additional criteria such as publication date, language, or study design. Pilot test your criteria on a sample of studies to ensure they are workable.
Managing the Screening Process
Screening a large number of records can be time-consuming. Use a systematic approach, such as screening in batches and tracking decisions in a spreadsheet or screening tool. The National Library of Medicine provides access to resources on systematic review methods that include guidance on screening processes.
Charting the Data
Charting is the process of extracting and organizing key information from included studies. This step is analogous to data extraction in a systematic review, but the goal is descriptive instead of analytical.
Developing a Charting Form
Create a form that captures the information needed to answer your research question. Common fields include:
- Author and year
- Country and setting
- Study design and methods
- Population and sample size
- Concept and context
- Key findings and outcomes
Pilot Testing the Form
Test your charting form on a small sample of studies before applying it to the full set. This helps identify missing fields, ambiguous items, and practical issues. Refine the form based on pilot testing.
Charting in Practice
Two reviewers should chart data independently, at least for a subset of studies, to ensure consistency. Discrepancies should be discussed and resolved. The charting process should be documented so that readers understand how the data were extracted.
Presenting Charted Data
Charted data are typically presented in tables that summarize the characteristics of included studies. These tables provide a visual overview of the evidence landscape and support the narrative summary.
Collating, Summarizing, and Reporting Results
The final stage of a scoping review involves organizing the charted data into a meaningful summary.
Narrative Summary
Write a narrative summary that describes the range of evidence, key concepts, and gaps in the literature. Organize the summary around themes or categories that emerge from the data. Use the charted data to support your descriptions.
Tables and Figures
Use tables to present study characteristics and key findings. Figures, such as maps or diagrams, can help illustrate the distribution of evidence across settings or populations. The EQUATOR Network provides guidance on reporting standards that apply to tables and figures.
Answering the Research Question
Your results should directly address your research question. If your question asked what types of evidence exist, describe the types and their distribution. If your question asked about key concepts, define and explain them. If your question asked about gaps, identify and discuss them.
Limitations
Discuss the limitations of your scoping review. These may include search limitations, language restrictions, or the absence of quality appraisal. Acknowledging limitations is a core principle of transparent research reporting.
At a Glance
| Review Stage | Key Actions | Common Outputs |
|---|---|---|
| Protocol development | Define the research question using PCC, plan the search strategy, register the protocol | Registered protocol document |
| Search and screening | Search multiple databases, screen titles and abstracts, review full texts | PRISMA flow diagram, list of included studies |
| Charting and reporting | Extract data using a charting form, summarize findings narratively and in tables | Data charting tables, narrative summary, gap analysis |
Selecting a Reporting Guideline
Reporting guidelines help ensure that your manuscript includes all necessary information. The EQUATOR Network is the primary resource for identifying reporting guidelines across study types.
PRISMA-ScR
The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews, known as PRISMA-ScR, is the standard reporting guideline for scoping reviews. It includes a checklist of items that should be reported in the title, abstract, introduction, methods, results, and discussion.
Using the EQUATOR Network
The EQUATOR Network provides a searchable database of reporting guidelines. You can search by study type or by specific guideline name. The site also provides resources on how to use reporting guidelines effectively.
When to Select a Guideline
Select your reporting guideline before you begin your review. This ensures that you collect the information needed for reporting as you go, instead of trying to reconstruct it at the end. The EQUATOR Network emphasizes the importance of transparent reporting for research integrity.
Records and Documentation
Maintaining detailed records is essential for a scoping review. Your records serve as the evidence that your review was conducted systematically and transparently.
What to Document
Document every stage of the review process, including:
- The protocol and any amendments
- Database searches, including dates and search strings
- Screening decisions and reasons for exclusion
- Charting forms and any revisions
- Decisions made during the review process
Organizing Records
Use a systematic approach to organize your records. This might include a spreadsheet for screening decisions, a folder for full-text PDFs, and a document for protocol amendments. The National Institutes of Health provides guidance on data management and sharing expectations that can inform your record-keeping practices.
Data Management
The National Institutes of Health requires researchers to plan for data management and sharing. While this policy applies to NIH-funded research, the principles are relevant to all researchers. Plan how you will store, organize, and share your review data before you begin.
Common Failure Patterns
Researchers conducting scoping reviews often encounter predictable problems. Recognizing these patterns can help you avoid them.
Unclear Research Question
A vague research question leads to an unfocused review. If your question is too broad, you will retrieve an unmanageable number of records. If it is too narrow, you may miss relevant evidence. Use the PCC framework to sharpen your question.
Incomplete Search Strategy
Searching only one database or using too few search terms will miss relevant studies. A comprehensive search strategy is essential for a scoping review. Document your search process so that others can replicate it.
Inconsistent Screening
When multiple reviewers screen studies, inconsistencies are common. Pilot test your inclusion criteria and screening process to improve consistency. Discuss disagreements and document resolutions.
Poor Documentation
Failure to document decisions and processes undermines the credibility of your review. Keep detailed records from the start. The Committee on Publication Ethics core practices emphasize the importance of transparency and accountability in research.
Overstating Findings
Scoping reviews describe the evidence landscape, they do not evaluate the quality of evidence or provide effect estimates. Avoid making claims about intervention effectiveness or evidence quality that your method does not support.
Ethics and Publication Considerations
Scoping reviews involve ethical considerations related to authorship, data management, and publication.
Authorship
The Committee on Publication Ethics core practices define authorship as requiring substantial contributions to the conception, design, data collection, or analysis of the work. All authors must approve the final manuscript and agree to be accountable for its content. Discuss authorship early in the project to avoid disputes.
Data Management
The National Institutes of Health data management and sharing policy requires researchers to plan for data management and sharing. Even if your review is not NIH-funded, following these principles demonstrates good research practice. Plan how you will store and share your search records, screening decisions, and charted data.
Conflicts of Interest
Declare any conflicts of interest, including financial, personal, or professional relationships that could influence your review. The Committee on Publication Ethics core practices require transparency about conflicts.
Peer Review
Scoping reviews should undergo peer review before publication. The Committee on Publication Ethics core practices describe the principles of fair and rigorous peer review. Respond to reviewer comments constructively and document changes to your manuscript.
Researcher Identity and Record Maintenance
Maintaining an accurate researcher identity is important for scoping review authors.
ORCID
ORCID provides a persistent digital identifier that distinguishes you from other researchers. An ORCID record links your research outputs, including scoping reviews, to your identity. This is particularly important if you have a common name or if your name changes.
Maintaining Your Record
The ORCID for Researchers resource explains how to create and maintain your ORCID record. Link your publications, datasets, and other research outputs to your ORCID identifier. Update your record when you publish new work or change institutions.
Integration with Publishing
Many journals and funders require ORCID identifiers. Including your ORCID in your manuscript submission helps ensure that your work is correctly attributed to you. The ORCID for Researchers resource provides guidance on integrating ORCID into your workflow.
Funding and Grant Considerations
If your scoping review is part of a funded project, you need to understand the funding requirements that apply.
NIH Grant Policy
The National Institutes of Health provides official guidance on grant policy, application, review, and award management. If your review is NIH-funded, you must comply with these policies, including data management and sharing requirements.
Budgeting for Your Review
Scoping reviews require time and resources. Budget for database access, reference management software, and personnel time for screening and charting. If you plan to publish in an open-access journal, budget for publication fees.
Compliance Requirements
The National Institutes of Health website provides information on compliance requirements for funded research. These may include progress reports, data sharing plans, and other administrative obligations.
Practical Implementation Steps
Follow these steps to conduct a scoping review from start to finish.
Step 1: Define Your Question
Use the PCC framework to develop a clear research question. Write down your question and review it with your team.
Step 2: Select a Reporting Guideline
Visit the EQUATOR Network and select the PRISMA-ScR guideline. Download the checklist and use it to plan your review.
Step 3: Develop and Register a Protocol
Write your protocol, including your research question, inclusion criteria, search strategy, and charting approach. Register your protocol in a public registry.
Step 4: Conduct the Search
Search multiple databases using a documented search strategy. Save all search results and record the date and search string for each database.
Step 5: Screen Studies
Screen titles and abstracts, then full texts, against your inclusion criteria. Use two reviewers and document all decisions.
Step 6: Chart the Data
Develop a charting form, pilot test it, and extract data from included studies. Document the charting process.
Step 7: Summarize and Report
Organize the charted data into tables and a narrative summary. Discuss the range of evidence and identify gaps. Report your findings according to the PRISMA-ScR checklist.
Step 8: Manage Your Records
Store all records, including search results, screening decisions, and charting forms. Plan for data sharing according to the National Institutes of Health expectations.
Frequently Asked Questions
How is a scoping review different from a systematic review?
A scoping review maps the breadth of evidence on a broad topic and does not typically include quality appraisal. A systematic review answers a focused question about effectiveness and includes a quality assessment of included studies.
Do I need to register my scoping review protocol?
Protocol registration is recommended and often required by journals and funders. Registration increases transparency and helps avoid duplication of effort.
How many databases should I search?
Search multiple databases relevant to your topic. The exact number depends on your field, but searching only one database is rarely sufficient for a comprehensive scoping review.
Can I change my protocol after registration?
You can amend your protocol, but you should document any changes and explain the rationale. This is consistent with the iterative nature of scoping reviews.
Do scoping reviews assess study quality?
Scoping reviews typically do not include a formal quality appraisal. The goal is to map the evidence, not to evaluate its quality.
What is the PRISMA-ScR guideline?
PRISMA-ScR is the reporting guideline for scoping reviews. It provides a checklist of items to include in your manuscript to ensure transparent reporting.
How long does a scoping review take?
The time required varies depending on the topic, the volume of literature, and the size of your team. A scoping review can take several months to a year or more.
Can a scoping review be updated?
Scoping reviews can be updated when new evidence emerges. An update should follow the same methods as the original review and document changes from the original.
Using the Evidence
| Source | Best use in this topic | Important limitation |
|---|---|---|
| Research Methods Resources | official guidance | Check the linked page for current local requirements |
| EQUATOR Network | official guidance | Check the linked page for current local requirements |
| Core Practices | official guidance | Check the linked page for current local requirements |
Related Articles
- Conducting a Study: A Practical Checklist for Life Science Researchers
- Conducting Qualitative Interviews: A Guide for Life Science Researchers
- Open Science Practices: A Practical Guide for Life Scientists
- What Is Data Management? A Primer for Life Science Researchers
- Master Data Management: A Practical Guide for Life Science Organizations
References and Further Reading
- Research Methods Resources. National Library of Medicine.
- EQUATOR Network. EQUATOR Network.
- Core Practices. Committee on Publication Ethics.
- NIH Grants and Funding. National Institutes of Health.
- ORCID for Researchers. ORCID.
- Data Management and Sharing Policy. National Institutes of Health.
- NCBI Literature Resources. National Center for Biotechnology Information.
- PubMed. National Library of Medicine.
This article is educational and does not replace institutional policy, professional advice, or applicable safety and regulatory requirements.