Scoping Reviews: A Bird’s Eye View

Evidence-based Healthcare is the “buzzword” in the recent era. Systematic reviews have gained immense interest to advocate an evidence-based healthcare practice. They are nothing but systematically collected, appraised, and synthesized evidence that helps determining the best choice amongst available treatment interventions for a clinical condition. However, there are several areas where enough randomized controlled trials are not available, comparative effectiveness research is not feasible. Thus, a novel concept called “scoping review” has been introduced in the research ecosystem. It aims at exploring the wide information spectrum and addresses broader research questions. mapping the evidence and thereby identifying the research gaps. ScRs may be undertaken as a precursor to a systematic review2. While conventional systematic reviews (SLRs) constitute the core of evidence synthesis, scoping reviews have a great potential to complement the evidence gaps realized in the overall knowledge synthesis landscape. Scoping reviews can be used for literature that exhibits a large, complex, and/or heterogeneous nature, which is not suitable for conducting systematic reviews. Scoping reviews can be used to develop ‘concept maps’ to explore the terminology related to a particular topic and ‘policy maps’ that trace relevant documents from government agencies and professional bodies.


Scoping reviews (ScR) can serve as tools for evidence reconnaissance. Depending on their comprehensive nature, they could be used for analyzing the breadth and depth of the literature. Moreover, they are used when it is required to get clarification upon working definitions of a certain clinical topic or determining conceptual boundaries or key characteristics. They are apt research methods to inform future research areas through broadly exploring the literature and mapping the evidence. Given their exploratory nature, they could be well-utilized to identify research gaps.

The decision for the choice between conventional SLR and ScR depends upon the underlying objective of the research. If the purpose is to answer a focused research question with stringent literature screening and data collection requirements, conventional SLR would be a good choice. On the other hand, if a researcher would like to know what all matter is available on a specific topic, Scoping reviews are highly recommended.

Applications of scoping review

Applications of scoping review


While the underlying objective of all types of SLRs is to gather the evidence, the difference lies in their contextual applications. Depending on the context, methodological differences are also evident4. The table below provides a high-level comparative summary of various procedural aspects of both SLRs and ScRs with examples:

  Interventional review Scoping review
Purpose Evidence synthesis to answer a discrete question Narrative or descriptive information without any specific focus on research question
Nature of Research question  Stringent Broad
Framework PICOs (Population, Intervention, Comparator, Outcome, Study design) PCC (Population, Concept, Context)
Study selection Limited to RCTs, SLRs and Observational studies No specific criteria
Data Extraction Systematic and specific Comprehensive to include most of the relevant information
Critical Appraisal Mandatory Not Mandatory but Desirable depending on the context5
Results Meta-analysis (forest plots)-quantitative synthesis Meta-aggregation- qualitative synthesis Overview of the literature (logical, diagrammatic, chart, tabular or descriptive format)
Example of Problem Statement Is COVAXIN safe and effective in children with juvenile diabetes? What are the different recommended course of action for treating COVID-19?
Do you think it’s difficult to undertake a scoping review? Well… here we provide a quick step-by-step guide to get it done effectively:

Scoping review process outline

  • Define the topic
The initial step is to identify the problem statement and define a set of research question(s) to develop a clear topic and objective.
  • Develop a scoping review protocol
A priori protocol development (using PRISMA-ScR) and registration is required on public portals like Open Science FrameworkFigshare, or JBI Synthesis Science Unit.
  • Finalize search strategy

Finalization of the search strategy is undertaken prior to the beginning of literature search. (Preferably with the mnemonic PCC (Population, Concept, and Context) framework as recommended by JBI). Unlike other systematic reviews, there is no need for explicit outcomes, interventions to be stated; however, it may be implicit in the concept.

  • Run a literature search
The three-step search execution strategy involves:
  1. Initial search using at least two databases, e.g., MEDLINE (PubMed, Ovid) or CINAHL, to identify all relevant keywords
  2. Search using all keywords and index terms in the included databases
  3. Snowball search, searching through reference list of the included articles
  4. Grey literature (difficult to locate or unpublished). It includes newsletters, internal reports, working papers, conference abstracts, unpublished trial data, patents, policies.
  • Data extraction/charting

The key information is recorded in a pre-structured data charting table. This will include but is not limited to demographic characteristics, interventions, findings of any comparative effectiveness research, safety data, and KOL (key opinion leader) recommendations.

  • Analysis and presentation of results

Data analysis in scoping reviews may include simple frequency counts (quantitative data) or descriptive presentation (qualitative analysis). It is recommended that authors plan well in advance on how the data will be presented, e.g., chart, table, or figure. The purpose of charting data is to identify, prioritize, summarize, and display gaps in evidence.

Genpro MW & RWE groups are supporting global partners for scoping review, Systematic Literature Review, and many other types of evidence-based reporting needs. Reach out to us at to understand how we can work with you to build customized solutions for real-world evidence (RWE), medical affairs, medical communications, market access, and scientific writing. We can support medical and scientific writing needs through our experienced writers located in the US, India, EU, and UK.

  1. Joanna Briggs Institute’s manual, 2nd edition
  2. Guidance for conducting systematic scoping reviews
  3. Current best practices for the conduct of a scoping review
  4. Update JBI model of evidence-based healthcare
  5. Scoping reviews- what they are and how can you do them

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