Reviews and Evidence Syntheses: Scoping or Mapping Review

A scoping review (also called a scoping study) is a type of evidence synthesis that maps the existing literature on a topic, identifying key concepts, theories, sources, and types of evidence available. Scoping reviews belong to the systematic review family and share processes with systematic reviews (e.g., comprehensive search and transparent documentation); while scoping reviews are sometimes mischaracterized as a "less rigorous systematic review,"  they are distinguished by broader aims and more inclusive criteria, including a wider range of study designs.

• Scoping reviews provide a preliminary assessment of the size, scope, and characteristics of the available research literature.
• Scoping reviews are typically undertaken when the topic is complex, varied, or has not yet been comprehensively reviewed.
• Unlike systematic reviews, scoping reviews do not involve synthesis, formal quality assessment or a critical appraisal of the included studies.

More on scoping reviews:

• Davis, K., Drey, N., & Gould, D. (2009). What are scoping studies? A review of the nursing literature. International journal of nursing studies, 46(10), 1386–1400. https://doi.org/10.1016/j.ijnurstu.2009.02.010

Primary Goals:

• To examine the extent, range, and nature of research activity in a topic area.
• To determine the value and feasibility of conducting a full systematic review.
• To summarize and disseminate existing research findings.
• To identify research gaps in the literature.

Key Features:

• Typically includes a broad research question and a comprehensive literature search (though the completeness of the search may depend on time or scope constraints).
• May involve ongoing research and grey literature.
• Often results in a literature map, conceptual map, policy map, or stakeholder consultation.
• Includes a descriptive summary rather than synthesis of findings.
• Findings are usually presented in tables with narrative commentary.

Strengths:

• Helps inform policy makers and researchers.
• Can be used as a standalone product or preliminary step toward a systematic review or primary research.
• Systematic, transparent, and replicable methods are emphasized.

Limitations:

• Lack of quality assessment introduces potential for bias.

The choice to conduct a scoping review should be guided by the purpose of the inquiry—especially useful when a topic is emerging, complex, or poorly defined. Arksey and O'Malley (2005) outlined a widely used six-stage methodological framework for conducting scoping reviews:

• The research question
• Identifying relevant studies
• Study selection
• Charting the data
• Collating, summarizing, and reporting the results
• (Optional) Consultation with stakeholders

Subsequent authors have expanded on and refined this framework:

• Daudt, H. M., van Mossel, C., & Scott, S. J. (2013). Enhancing the scoping study methodology: a large, inter-professional team's experience with Arksey and O'Malley's framework. BMC medical research methodology, 13, 48. https://doi.org/10.1186/1471-2288-13-48
• Levac, D., Colquhoun, H., & O'Brien, K. K. (2010). Scoping studies: advancing the methodology. Implementation science : IS, 5, 69. https://doi.org/10.1186/1748-5908-5-69

Campbell Collaboration's suggested title format: [Review concept] in [population/s] in [context]: A scoping review

More guidance:

• Munn, Z., Peters, M. D. J., Stern, C., Tufanaru, C., McArthur, A., & Aromataris, E. (2018). Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach. BMC medical research methodology, 18(1), 143. https://doi.org/10.1186/s12874-018-0611-x
• Peters MDJ, Godfrey C, McInerney P, Munn Z, Tricco AC, Khalil, H. Scoping Reviews (2020). Aromataris E, Lockwood C, Porritt K, Pilla B, Jordan Z, editors. JBI Manual for Evidence Synthesis. JBI; 2024. Available from: https://synthesismanual.jbi.global.  https://doi.org/10.46658/JBIMES-24-09
• PRISMA for Scoping Reviews (PRISMA-ScR): https://www.prisma-statement.org/scoping (checklist)

• Brien, S. E., Lorenzetti, D. L., Lewis, S., Kennedy, J., & Ghali, W. A. (2010). Overview of a formal scoping review on health system report cards. Implementation science, 5, 2. https://doi.org/10.1186/1748-5908-5-2
• Murmann, M., Reed, A. C., Scott, M., Presseau, J., Heer, C., May, K., Ramzy, A., Huynh, C. N., Skidmore, B., Welch, V., Little, J., Wilson, K., Brouwers, M., & Hsu, A. T. (2023). Exploring COVID-19 education to support vaccine confidence amongst the general adult population with special considerations for healthcare and long-term care staff: A scoping review. Campbell Systematic Reviews, 19, e1352. https://doi.org/10.1002/cl2.1352

• Anderson, S., Allen, P., Peckham, S., & Goodwin, N. (2008). Asking the right questions: Scoping studies in the commissioning of research on the organisation and delivery of health services. Health Research Policy and Systems, 6(7). https://doi.org/10.1186/1478-4505-6-7
• Arksey H. & O’Malley, L. (2005). Scoping studies: Towards a methodological framework. International Journal of Social Research Methodology: Theory and Practice 8(1): 19–32. https://doi.org/10.1080/1364557032000119616 
  [Repository copy: https://eprints.whiterose.ac.uk/id/eprint/1618/1/Scopingstudies.pdf]
• Brien, S. E., Lorenzetti, D. L., Lewis, S., Kennedy, J., & Ghali, W. A. (2010). Overview of a formal scoping review on health system report cards. Implementation science, 5, 2. https://doi.org/10.1186/1748-5908-5-2
• DiCenso, A., Martin-Misener, R., Bryant-Lukosius, D., Bourgeault, I., Kilpatrick, K., Donald, F., Kaasalainen, S., Harbman, P., Carter, N., Kioke, S., Abelson, J., McKinlay, R. J., Pasic, D., Wasyluk, B., Vohra, J., & Charbonneau-Smith, R. (2010). Advanced practice nursing in Canada: overview of a decision support synthesis. Nursing leadership (Toronto, Ont.), 23 Spec No 2010, 15–34. https://doi.org/10.12927/cjnl.2010.22267
• Grant, M. J., & Booth, A. (2009). A typology of reviews: An analysis of 14 review types and associated methodologies. Health Information & Libraries Journal, 26, 91–108. https://doi.org/10.1111/j.1471-1842.2009.00848.x
• Mays, N., Roberts, E., & Popay, J. (2001). Synthesising research evidence. In N. Fulop, P. Allen, A. Clarke, and N. Black (Eds.), Studying the organization and delivery of health services: research methods, (188-220). Routledge. [OhioLINK: https://olc1.ohiolink.edu:443/record=b21026617]
• Pham, M.T., Rajić, A., Greig, J.D., Sargeant, J.M., Papadopoulosa, A. & McEwena, S.A. (2014). A scoping review of scoping reviews: Advancing the approach and enhancing the consistency. Research Synthesis Methods, 5, 371–385. https://doi.org/10.1002/jrsm.1123
• The Campbell Collaboration. Campbell systematic reviews: Policies and guidelines. Campbell Policies and Guidelines _May3 2022.docx

• Thomas, A., Lubarsky, S., Durning, S. J., & Young, M. E. (2017, Feb). Knowledge syntheses in medical education: Demystifying scoping reviews. Academic Medicine, 92(2), 161-166. https://doi.org/10.1097/ACM.0000000000001452 

• A mapping review (also called a systematic map, evidence map, or systematic mapping review) aims to map out and categorize existing literature in a specific area to identify research gaps and guide decisions about future research or systematic reviews.

• Mapping reviews are typically used when addressing questions of effectiveness and are particularly concerned with what evidence exists on a broad topic.

• They do not include formal quality appraisal and tend to remain at a descriptive level, providing an overview of the characteristics of available studies.

• Originated to help structure evidence for decision-making and future review planning

Primary Goals:

• To identify gaps in research literature from which further reviews or primary research may be commissioned.
• To contextualize more focused systematic reviews within a broader research landscape.
• To support policy-relevant decision-making by categorizing evidence across variables like population, setting, intervention type, and study design.

Key Features:

• Driven by specific research questions, often related to intervention effectiveness; uses frameworks like PICO (Population, Intervention, Comparator, Outcome).
• Literature is coded and categorized by characteristics such as methodology, intervention type, population, or setting.
• Results are typically tabular or graphical, enabling visual mapping of evidence.
• Completeness of search is constrained by available time and scope.
• No formal quality assessment is conducted, which limits the depth of analysis.
• Descriptive, not analytical—focused on characterization rather than synthesis.

Strengths:

• Provides a broad overview of a topic.
• Useful for setting research priorities and justifying funding decisions.
• Helps determine whether enough similar studies exist for a focused systematic review.

Limitations:

• Lacks synthesis and quality appraisal, which can lead to oversimplification or masking of study heterogeneity.
• Outcomes are not always clear-cut, as they may or may not lead to additional reviews or primary research.
• Can be time-consuming and resource-intensive, especially if coding schemes are complex.

Exemplar Articles

• Tybor, D. J., Beauchesne, A. R., Niu, R., Shams-White, M. M., & Chung, M. (2018). An evidence map of research linking dietary sugars to potentially related health outcomes. Current Developments in Nutrition, 2(11), nzy059. https://doi.org/10.1093/cdn/nzy059
• Wijn, S. R. W., Rovers, M. M., & Hannink, G. (2022). Confounding adjustment methods in longitudinal observational data with a time-varying treatment: a mapping review. BMJ Open, 12(3), e058977. https://doi.org/10.1136/bmjopen-2021-058977

• Miake-Lye, I. M., Hempel, S., Shanman, R., & Shekelle, P. G. (2016). What is an evidence map? A systematic review of published evidence maps and their definitions, methods, and products. Systematic Reviews, 5(1), 1-21. https://doi.org/10.1186/s13643-016-0204-x