Scoping Review

Set up a systematic search strategy

In order to write a scoping review, you must systematically search the available literature. You do this by using a predetermined search string and by choosing the appropriate databases. You may also limit the time frame in which you search, and/or type of literature and/or language. These decisions are documented in your research protocol.  

Determine your research question and associated search terms
Two important components of a research protocol are the research objective and the research question. In the research objective, you describe: 

• why the review should be conducted;
• what the review will add to the relevant research domain; 
• what exactly is your topic of investigation;
• why the review should be conducted;
• what the review will add to the knowledge in the relevant research domain; 
• what exactly will be investigated about the chosen topic

During a scoping review, one or more main or sub-questions may be answered. As with other types of research, it is recommended that you phrase your questions as specifically as possible.

Creating and testing the search string is an iterated process: you can determine whether your research question and search terms lead to the desired (amount of) results, and you can add and remove search terms based on your search results. At this stage, you can still adjust your research question and search string.

A good search string is the basis of your scoping review. A useful research question framework for determining the right search terms for a scoping review is "PCC": "Population," "Concepts," and "Context. Example: 

Question: What nurse-led models of care are used to manage chronic disease for middle-aged women in high-income countries? 

P - Population - middle-aged women 
C - Concept - Chronic disease, nurse-led models of care 
C - Context - High-income countries 

Once you have determined the relevant keywords, it is important to add synonyms to your search string to find more relevant articles. In addition, you can also use "controlled search terms" by using a database's thesaurus. These are search terms that database editors have assigned as metadata to publications, and are called 'subject terms' or 'subject headings' (depending on the database).

Important elements in a search string are Boolean operators (AND, OR, NOT) and truncation (e.g. adapt* for all terms beginning with the letters 'adapt': adaptation, adapted, adapts, etc.). This allows you to systematically capture all combinations of relevant search terms and their synonyms in one search string.  

Do you search multiple databases? Not every database uses operators, filters and truncation in the same way. Therefore, customize your search string for each database.  

Finally, it is recommended that you use an information log to keep track of which modifications to your search string produce which results.

Determine which databases you want to consult

In a scoping review, you have the freedom to consult sources other than just scientific literature. If a lot of scientific literature can be found on your topic you can limit yourself to this. However, for other topics policy documents may also contain relevant information. 

For your search, it is recommended that you choose one or two general databases and on or two subject-specific databases. As general databases you should use Scopus and/or Web of Science. Both databases have a very comprehensive indexing of the available literature and are not limited to one publisher (which is the case with Elsevier's ScienceDirect database, for example). Web of Science and Scopus are available through the University of Groningen Library (RUG-L), and requires a guest user account for the University Library collection. You can put in a request for a GVO with the program manager of your research center. RUG affiliates do not need a GVO, as they already have access to the RUG-L collection. 

Examples of subject-specific databases are Psychinfo, ERIC, Communication & Mass Media Complete and PubMed.  

If you want to include gray literature in addition to scientific literature, use e.g. WorldCat or Google Scholar (for books, working papers, conference papers and more), or contact the Information Specialist at your research center for more information.

Write the research protocol
Document the final version of your question statement, search string, chosen data beacons and selection criteria in a research protocol. 

• "Development of a scoping review protocol," chapter 11.1, JBI Manual of Evidence Synthesis. See also the accompanying scoping review protocol template.
• Webinar: How to conduct and report your scoping review: latest guidance (JBI, 2020). 

Register your protocol
Depending on the journal in which you plan to publish, one option is to register your protocol prior to conducting your research. This is called "pre-registration". You send your analysis plan to the journal and make an agreement with the editor that your article will be published regardless of the outcome of the results.

• More on pre-registration
• The 'Open Science Framework' has an overview of journals that offer the option of pre-registration. You can also search for registered protocols. 
• Example of a registered scoping review protocol by a Hanze researcher: Kloosterman, L. M., & Jager-Wittenaar, H. (2022, Mar 14). Functioning of patients with lipedema: a scoping review. Open Science Framework. https://osf.io/2tqg3/

Preregistration of your protocol is optional. Alternatively, you may publish your protocol on an online platform to contribute to the transparency of your research. You can do this in Pure, the research information system of Hanze University or on platforms such as OSF or Figshare for a DOI.

Conduct your search
Once you have determined and documented the final search string in the research protocol, you will start conducting searches in the selected databases. You export the results from each database to a reference manager, such as RefWorks.

De-duplication
Before selecting articles for content, it is advisable to deduplicate the articles first. You can use a reference manager such as RefWorks for this as well. Note: for deduplication, it is better not to use Mendeley, as this application is not transparent about which articles it removes.

Screening of articles
An important step in a scoping review is the screening of the articles you found with your search string and any additional search methods. This is usually done in two steps: First, you screen based on what is in the abstracts. Secondly, you screen articles based on their full content.

It is recommended that you use a tool for screening the articles. A widely used tool for this purpose is Rayyan, an online tool which allows screening with two or more colleagues. Any disputes are automatically detected by Rayyan, which can be resolved later. Alternative programs that can be used are Covidence (paid), reference managers such as RefWorks, and Excel.

PRISMA Flow diagram

In order for your review to be published,  you must provide insight into how you conducted your review. Moreover, sharing your search strategy increases the transparency and reproducibility of the literature review. To do this, you document how many articles your final search string in yielded per database, how many articles remain after deduplication, how many articles were extracted and remain after applying inclusion and exclusion criteria. A useful tool to document this is the PRISMA Flow Diagram. 

Template for analyzing your results
It is also important to properly document your inclusion and exclusion criteria and to record the details of the included articles. The JBI has developed a useful template for this purpose: The JBI template source of evidence details, characteristics and results extraction tool. 

Templates for reporting

Both PRISMA and JBI have developed a checklist/template for reporting a scoping review. This provides an overview of all the elements that should be included in a scoping review article or report, as well as guidance on content and/or format.  

• PRISMA-ScR guidelines for scoping reviews: https://prisma-statement.org/Extensions/ScopingReviews This website contains an overview of 22 items to report on your scoping review. 
• Chapter 11.3, JBI Manual for Evidence Synthesis: The scoping review and summary of the evidence. 

Tools for 'orientation' phase:

• Link to the decision making tree: What review is right for you
• Video "Systematic vs scoping review | Which is right for your research question?"

Tools for 'preparation' phase:

• JBI protocol for scoping reviews (tool for writing your review protocol) 
• ’Development of a scoping review protocol’, chapter 11.1 of JBI Manual of Evidence Synthesis

Tools for 'execution' phase:

• Reference manager (e.g.. RefWorks)
• Screening tool: Rayyan. 
• PRISMA Flow diagram for documenting your systematic search

Tools for 'reporting' phase:

• JBI template source of evidence details, characteristics and results extraction instrument
• Chapter 11.3, JBI Manual for Evidence Synthesis: The scoping review and summary of the evidence (for reporting your review)
• Webinar: How to conduct and report your scoping review: latest guidance (JBI, 2020). 
• PRISMA-ScR guidelines for scoping reviews:  an overview of 22 items that should be included in your scpoing review paper;

Scoping review papers written by Hanze researchers (Open Access available):

• Bunt, S., Steverink, N., Olthof, J. et al. Social frailty in older adults: a scoping review. Eur J Ageing 14, 323–334 (2017). https://doi.org/10.1007/s10433-017-0414-7 
• Lentferink, A., Oldenhuis, H., Kulyk, O., de Groot, M., Polstra, L., Velthuijsen, H., Hermens, H., & van Gemert-Pijnen, L. (2016). Self-tracking and persuasive ecoaching in healthy lifestyle interventions: work-in-progress scoping review of key components. Paper presented at 4th International Workshop on Behavior Change Support Systems, Salzburg, Austria. 
• Konradsen, H., Brødsgaard, A., Østergaard, B., Svavarsdóttir, E., Dieperink, K. B., Imhof, L., Luttik, M. L., Mahrer-Imhof, R., & García-Vivar, C. (2021). Health practices in Europe towards families of older patients with cancer: a scoping review. Scandinavian Journal of Caring Sciences, 35(2), 375-389. https://doi.org/10.1111/scs.12855

If you have questions, please contact the Information Specialist Research of your research center, or go to support & contact for more information and advice.