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Systematic Search for Systematic Review

This guide aims to provide advice and resources for doing a systematic review.

FAQs on Literature Search for Conducting SR

1. How can I make my search more comprehensive?

2. How can I make my search more specific to my research question?

3. How can I find more synonyms and alternative terms?

4. Is my search strategy correct?

5. Subject headings vary in different specific databases to Health Sciences. How can I replicate my search?

6. I find duplicate records from different databases. What can I do?

1. How can I make my search more comprehensive?

You are suggested to combine Keyword searching and Subject Heading searching in subject-specific databases. 

Identify relevant subject headings (e.g. Medical Subject Headings MeSH for PubMed/Medline/Cochrane Library, Emtree for Embase, CINAHL Subject Headings for CINAHL Complete, Thesaurus of Psychological Index Terms for PsycINFO) and include them in your search. 

Make use of the "Explode" feature in your search term in subject-specific databases. When you explode a term, you create a search query that retrieves references indexed to the term and also references to narrower subject terms in the tree hierarchy of the subject heading. 

No single database includes all the literature for your research question. And different databases have their specific features and limiters that offer strengths in searching. So, search different databases to make your literature reach extensive retrieving unique records in each database. 

More searching tips on Boolean Operators, Truncations, and Phrase Search can be found here. 

2. How can I make my search more specific to my research question?

Make use of the "Subheadings" and "Major" feature in your search in subject-specific databases.

  • Subheadings restrict your subject heading in a certain context, i.e. the "aboutness" of the subject heading in your search. You can refer to the Scope Note to the scope of each subheading. 
  • When you make a subject heading a Major Concept / Major Focus, you create a search query that finds references in which the subject heading is a major point of discussion of the article. The references retrieved in the search result list are only articles with the subject heading as a main concept. 

3. How can I find more synonyms and alternative terms?

  • Some databases suggest synonyms and alternative terms when you search your keyword, e.g. Embase, Ovid Journals, and EBSCOhost platforms, including Medline and CINAHL Complete. You can decide if these suggested terms are relevant to your research question and include the relevant ones.

  • You can also search your keywords in reference work databases, e.g. Credo Reference. Not only can you find credible information on your topic from dictionaries, encyclopaedias, handbooks and manuals, you can also make use of its Mind map tool to explore related terms and concepts. 

  • Refer to the section on index terms or author keywords or subject headings in the articles you located to identify more relevant terms.  

4. Is my search strategy correct?

Searching is an iterative process. There is no right and wrong in a search strategy. Along the process, you may discover new keywords, and it is common to refine your search strategy or even your research question. It is difficult, if not impossible, to come up with a perfect search strategy in one go. 

The research cycle looks like this: 

Saunders, M., Lewis, P., & Thornhill, A. (2015). 
Research Methods for Business Students: Vol. Seventh edition. Pearson.

5. Subject headings vary in different specific databases to Health Sciences. How can I replicate my search?

True, for example, MeSH terms in PubMed/Medline may not be necessarily the same as Emtree terms in Embase. So, you cannot copy and paste search strategies directly in one database to another. You have to search the relevant subject heading in a subject-specific database to a keyword and translate the syntax e.g. the use of truncations of your already built search strategies to make them understandable and searchable in this particular database. 

You can replicate your search in multi-disciplinary databases e.g. Scopus and Web of Science. As they are not subject-specific databases, there are no subject headings in them. You can only conduct keyword searching of your search terms. 

6. I find duplicate records from different databases. What can I do?

It is common to find same records from different databases. Each database has its own unique records and also overlapping records with other databases, especially those with similar disciplinary focus in the same subject areas. You have to remove duplicate records by de-duplication before screening. You can remove duplicate records within each database and across all databases. Click here to find the steps to remove duplicate records with the use of the reference management tool EndNote, based on your customized Find Duplicates Search.