This guide outlines the recommended approach to literature searching using the following steps:
Select relevant resources for your topic from the A-Z Resources. The A-Z Resources page lists all the library resources including databases, clinical summaries, and collections of journals from particular publishers. If you are doing a literature review, we recommend that you search the key databases for your subject area.
The key databases for medicine and pharmacy are PubMed/Medline, Embase, and Cochrane. The key database for nursing and physiotherapy is Cinahl. In the introduction to this guide we recommend the key databases that are relevant for each subject area.
If you are writing a dissertation, thesis, systematic review, clinical guideline, or a journal article it is essential to search PubMed/Medline, Embase, Cochrane, Web of Science, and Scopus as well as the key subject databases.
Clarify your topic: divide your topic into separate aspects, and identify all keywords and synonyms for each aspect of your topic to ensure your approach is structured and comprehensive.
Separate searches: carrying out separate searches for each part of your topic allows you to see what has been published on each aspect and gives 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.
Keyword searches: Keyword Searches use your words / freetext to find your terms mentioned anywhere in the article title/abstract/record. Carry out keyword searches for each aspect of your topic separately, using truncation or phrase searches as appropriate, to find articles that mention your topic.
Truncation with * or $ finds different word endings: eg transplant* will find transplant, transplants, transplanted or transplantation.
Phrase searches uses inverted commas to find your words beside each other in the same sentence: eg "reflective practice"; "chest pain"; "hand washing". Adjacency Searching will find words located near eachother.
Limits Refine Results gives you options to reduce the numbers of your results. It is not recommended to limit to Full Text, as you may miss relevant items that do not have the pdf in this particular database.
Subject Heading searches: Subject Headings indicate the main topics of a paper using terms from the database thesaurus of Subject Headings (MeSH in Medline/PubMed, Cinahl Headings, Emtree in Embase). Do Subject searches on each aspect of your topic separately to find articles where your topics are main subjects within the paper. PubMed automatically maps your own keywords to MeSH terms. Medline and CINAHL have an option to “Suggest Subject Terms” to match your own keywords to MeSH or Cinahl Headings. Embase has options to “Map to Emtree Terms” in the Advanced Search Mapping tab. The subject heading searches have a code [MH] in Medline or Cinahl, MeSH in PubMed, or /exp in Embase.
It is recommended that you do both Keyword and Subject Heading searches to ensure that you don’t miss any potentially relevant articles. See our short video explaining subject headings here.
Combine your searches using OR and AND: 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 AND or Combine with OR. Combine searches of similar meaning with OR; eg cancer OR oncology OR neoplasms. Combine searches of different meaning with AND; eg cancer AND treatment. You can combine your keyword and Subject Heading searches on each aspect of your topic with OR so you get a subtotal for each aspect of your topic. Then you can combine all your subtotals together with AND to find articles that discuss ALL aspects of your topic.
Sample Search Terms for topic on feelings of guilt after receiving a kidney transplant
|kidney OR renal OR nephrology OR [MH]Kidney OR [MH]Kidney Failure||500|
|S2||transplant OR [MH]Transplantation OR [MH]Transplant Recipient OR [MH]Organ Transplantation||2000|
|S3||guilt OR emotion OR feeling OR coping OR acceptance OR [MH]Guilt OR
[MH]Emotions OR [MH]Quality of Life OR [MH]Adaptation, Psychological
|S4||S1 AND S2 AND S3||44|
Save your searches: 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 can easily re-run it any time without typing in the whole search again, and you have an accurate record of your search strategy. You can add relevant articles to your folder for future reading, or to export a set of articles to reference management software such as EndNote. It can be useful to export results from each database into EndNote to de-duplicate results if you have large quantities of results on your topic.
Citation searches: when you have selected articles for your bibliography/reference list, search for each article title in Scopus and click on Cited By to find more recent articles that have cited the paper since it was published. You can also search for known authors in Scopus to check for other articles by these authors that are not listed in Medline or Embase.
The following paragraph is an example of how to write up your search strategy in your literature review. It can be amended to suit your own topic. The sample topic is anti-depressants, quality of life, cardiac patients. Items in italics and brackets are optional where you add in what is required or relevant in your own write-up. It can be useful to look at standard formats for search strategy paragraphs in articles published in your field, and in particular journals you'd like to publish in.
"A comprehensive literature search was conducted in PubMed, Embase (include the platform if appropriate eg Elsevier / www.embase.com), PsycInfo (Ebsco or Ovid platform as appropriate) and Cochrane databases using keywords, synonyms and subject headings (insert date if required eg: in April 2022 / on 25th April 2022). MeSH headings were used in PubMed and Cochrane, Emtree headings were used in Embase, and APA Psychological Terms were used in PsycInfo. Separate searches on each aspect of the topic found that there were large numbers of papers published on each topic. When the searches were combined there were very few results, indicating a gap in the literature and suggesting the need for further research on the impact of anti-depressants on quality of life for cardiac patients. No language filter was applied as this would create a bias in the literature review as it would automatically exclude potentially useful articles that were originally published in other languages. A date limit of 5 years was applied to the result set in order to focus on recent research. A total number of xx papers were found in the database searches, following the removal of xx duplicates, of which xx were selected for inclusion using the following inclusion and exclusion criteria: (insert your exclusion and inclusion criteria here if appropriate). Additional relevant papers were identified through reference searching, citation searching in Scopus or PubMed, and grey literature searches using Google Scholar and relevant national and international sources including HSE and Lenus, NHS, Department of Health, WHO and patient organisations websites and reports (delete/add in whatever sources you had used). A PRISMA chart (see appendix) provides further detail on the search strategy results. The literature search indicated that extensive research has been published on patients' quality of life generally, and on quality of life in relation to depression, but very little of this is focused on renal patient cohorts/groups in particular and this reflects practitioner experience in the (insert your current setting / hospital setting / community setting etc - describe your own setting if appropriate or required). This (narrative / systematic / scoping / literature etc describe the kind of review you are doing etc) review provides an overview of the key themes arising from the literature found, critically appraises the literature, and highlights areas needing further research for the improvement of (patient care / quality of life for this cohort etc)."
Sample search strategy written up in published articles include:
Carroll P, Dervan A, Maher A, et al. (2021) Patient and Public Involvement (PPI) in preclinical research: A scoping review protocol. HRB Open Res. 4:61. https://pubmed.ncbi.nlm.nih.gov/34522837/
Fortune J, Murphy P, Merchant N, Kerr C, et al. (2020) Transition from child-centred to adult-oriented healthcare systems for young people with neurodisability: a scoping review protocol. HRB Open Res. 3:61. https://pubmed.ncbi.nlm.nih.gov/33215059/
Spooner M, Duane C, Uygur J, et al. (2022) Self-regulatory learning theory as a lens on how undergraduate and postgraduate learners respond to feedback: A BEME scoping review: BEME Guide No. 66. Med Teach; 44(1):3-18. https://pubmed.ncbi.nlm.nih.gov/34666584/