Systematic Reviews: Conduct Literature Searches

The aim of a systematic search is to uncover all relevant results related to your topic. Since systematic review searches can be extensive and yield a large volume of results, it is crucial to minimize the number of irrelevant results that need to be screened later on. In this part, you and your team will create search strategy to find these relevant articles. 

1. Decide on the main concepts of your topic.
2. Decide which databases are appropriate to search.
3. Decide on key search terms, including related terms.
4. Use more advanced search strategies like field tags and Boolean operators. 
5. Document and save your search strategy with notes about your search for later use.

Determine which databases are appropriate to search for your topic or field of interest. They can be multidisciplinary or subject-specific. Databases include articles from multiple journals, which is why it is important to search many databases for your review. You can access Brenau's full list of databases here. 

When performing a literature search, you want to uncover as many relevant articles as possible using key terms or controlled vocabulary. You expand on each key term by thinking of synonyms or related words that might reveal different results.

Example PICO Question

1. Identify the primary search concepts and terms from the research question. Consider terms with different spelling (British v. American English), Acronyms, etc. To find these terms look in encyclopedias, google, or journal articles.

Controlled Vocabulary

Controlled vocabulary is a standardized set of terms and phrases used consistently to describe and categorize information. This practice ensures that everyone uses the same terms in the same way, which improves the accuracy and efficiency of information retrieval and data management. 

Depending on the database, controlled vocabulary might be called different names.

• CINAHL - CINAHL Headings
• MEDLINE - MeSH
• Academic Search Complete - Subject Terms
• PsychArticles - APA Thesaurus of Psychological Index Terms

Nesting

A technique used to group search terms together using parentheses to control the order in which the search terms are processed. This helps create more precise and effective search queries, especially when combining multiple keywords with Boolean operators (AND, OR, NOT).

ALWAYS combine terms for a single concept inside one set of parenthesis. 

Example:

(exercise [MeSH] OR "physical activity" OR "Physical Conditioning" OR "Endurance Training")

Field Tags

Field tags are specific identifiers used to limit the search to particular fields within a record. These tags help refine searches by specifying where the search terms should appear, such as in the title, author, abstract, or subject fields. 

For systematic review searching, best practice is to apply field tags to each term for reproducibility.

When you combine these strategies, your search string may look like this:

(exercise [MeSH] OR "physical activity" [AB] OR "Physical Conditioning"[AB] OR "Endurance Training" [AB]) AND ("insulin resistance" [AB] OR "insulin resistant" [AB] OR "insulin sensitivity" [AB] or "insulin resistant diabetes" [AB]) AND ("adolescent [TX] OR teen [TX] OR Teenager [TX] OR Teenagers [TX] OR Youth [TX])

Grey literature refers to research that is not published through traditional commercial publishing channels. In the context of a systematic review, grey literature can include a variety of sources, such as:

• Technical reports produced by government agencies, NGOs, and other organizations.
• Conference proceedings and abstracts that may not be published in journals.
• Theses and dissertations from academic institutions.
• Preprints of articles that are not yet peer-reviewed or formally published.
• White papers and policy documents from think tanks or research institutions.
• Unpublished studies and raw data sets.
• Institutional and internal reports from corporations or organizations.
• Clinical trial registries and databases.
• Government publications and documents.
• Patents and standards.

Incorporating grey literature into a systematic review is crucial because it helps to:

• Reduce publication bias: Traditional published studies are more likely to report significant findings, whereas grey literature can include studies with null or negative results.
• Enhance comprehensiveness: Including a broader range of sources provides a more complete picture of the available evidence.
• Improve robustness: Grey literature can contribute additional data and perspectives that strengthen the review's conclusions.

Google Scholar

Google scholar is only a supplementary source. Results fluctuate and you must acknowledge constraints.

• Predetermine your search method BEFORE searching begins  (no nesting, truncation, synonym searching, etc.)
• Focus on relevancy NOT Recall
• View only the first 50 results
• Take into account limitation, bias
• Create a Google custom search engine

Using AI Tools for Research: Benefits and Cautions

You may choose to supplement your database searching with Artificial Intelligence (AI) tools such as ChatGPT, Elicit, Scite, or other research assistants. These tools can offer helpful features, such as:

• Chat-style interaction to refine your research question

• Identification of recent publications, including pre-prints

• Access to more open-access literature

• Summarization of articles or key concepts

However, use caution when incorporating AI into your research process:

• Hallucinated (fake) citations: AI tools may generate references that do not exist or misattribute information.

• Inaccurate summaries: Summaries may oversimplify or misrepresent complex findings.

• Limited access to full-text: AI tools may not access the same full-text scholarly databases your library provides.

• Lack of peer review: Not all suggested sources may be scholarly or peer-reviewed.

Best Practices:

• Always verify citations in your library’s databases or Google Scholar.

• Use critical appraisal tools to assess the credibility and quality of sources.

• Do not rely solely on AI for literature reviews or evidence synthesis.

• When in doubt, consult a librarian or your professor.

AI can be a helpful starting point, but should never replace rigorous, scholarly research methods.

Record. Report. Repeat

Documentation is important for transparency and replicability. For any questions that may arise throughout the review process, you can return to your notes for an answer. Additionally, any peer-reviewers who are assessing your review will want to know your process and intent.

Good Evidence = Good Healthcare.

1. Registers, websites, organizations, other sources searched
2. Date when each source was last searched or consulted
3. Full Search Strategies
4. Any Filters or Limitations Used

*Note the rationale for database selection, choice of searchable concepts, tested/excluded terms, field for keyword searching, line combos, filters, etc. so your team understands.
*Note citations for definitions used.
*Create a list of validation articles that support why the study is needed.
 

Can't find the full text?

ASK US! 

Request an article or book .

You can also Ask a Librarian about visiting one of our partner libraries.