Open Resources for All

Identify the key concepts within your research question.  Write a list of all keywords and synonyms for each of these key concepts.  This means your search will be comprehensive.  Select relevant databases to search for your topic.  Using the following structured approach to searching across all relevant databases ensures your literature review is systematic and comprehensive. 

Doing separate searches for each part of your topic allows you the flexibility to combine the various aspects of your topic in different ways to yield further results, particularly if the combination of all aspects of your topic finds too few results.  This approach highlights which areas are well-researched and which areas are under-researched.  This may provide useful context that identifies gaps in the literature that may reflect your experience in practice.   

A keyword search will find your words anywhere in an article record.  If you find too many results you may decide to try a Title/Abstract search for your keywords instead.   

You can do a phrase search by using “inverted commas” to find commonly used phrases where the words are beside each other in the same sentence.  Phrase searches are useful particularly if the words are often used separately within different contexts and meanings.   

You can use truncation to find different word endings.  Different databases use different symbols for truncation, such as * or $.  For example transplant* will find transplant, transplants, transplanted, transplantation.  You cannot use truncation and phase searches at the same time because the phrase search will find the exact characters in order, but authors will not be writing an * in their sentences.   

Subject Headings are added to journal article records in the databases in order to indicate the main topics of the paper.  Each database has a standardised list/thesaurus of subject terms to ensure consistency: MeSH in Medline/PubMed; Cinahl Headings in Cinahl; Emtree terms in Embase.  Searching for subject headings on each aspect of your topic ensures your search is comprehensive so as not to miss any potentially relevant papers.  PubMed automatically maps your own keywords to MeSH terms.  In other databases, click on the thesaurus and search for relevant subject headings as well as doing the keyword searches.  In your Search History the subject heading searches will have a code to differentiate them from your own keyword searches, for example [MH] in Medline or Cinahl, MeSH in PubMed, or /exp in Embase.  See our short video explaining subject headings here. 

Your Search History shows your sets of results for each search.  You can combine your searches by selecting them in the Search History list, and choosing Combine with OR or Combine with AND.  Combine searches of similar meaning first with OR, for example: cancer OR oncology OR neoplasms.  Then combine searches of different meaning with AND, for example (cancer OR oncology OR neoplasms OR carcinoma) AND (treatment OR drug therapy OR chemotherapy OR radiotherapy).  

Refine Results gives you options to reduce the numbers of your results using various limits or filters, for example for age group, patient gender, systematic review.  It is not recommended to limit to Full Text, as you may miss relevant items that do not have the pdf in a particular database. 

Every database has options to register and create a personal folder to sign in or login to.  You can save articles or searches to your folder.  It is very useful to Save Searches if you need to run a search again to check for newly published items on your topic.  Saving your search means that you have an accurate record of your search strategy if it needs to be written up or included as an appendix in your work.  You can add relevant articles to your folder for future reading, or to export a set of articles to reference management software.    

After you have selected articles for your bibliography/reference list, search for each article title or author name in PubMed (or a citation database, or Research Gate) to check for newer citations or additional similar articles by a known expert in a clinical specialty.  

PubMed help pages providing a PubMed User Guide