How to undertake a literature search

First, write out your title and check that you understand all the terms. Look up the meaning of any you don’t understand. An online dictionary or medical encyclopaedia may help with this.

If your search is for a dissertation, you may need to choose your own research question. In this case, you will need to consider whether there is likely to be enough research on your topic. Alternatively, if your topic is too broad, you could be overwhelmed by the number of references.

One way of checking how much is written on your topic is to use Library Search. Most libraries offer a Library Search or discovery tool. It provides a quick search across all the library’s holdings. You can also limit your search by date or type of document. If you just need a few references to help you write an essay, Library Search may be helpful. It also gives quick access to full text items.

Next, you need to identify your key concepts. One way to do this is to look at your title and identify the most important words. Ignore words that tell you what to do with the information you find eg evaluate, assess, compare, as these are not generally used as search terms. In the example below, key concepts have been highlighted:

Evaluate the effectiveness of a mindfulness intervention on the health-related quality of life of rheumatoid arthritis patients

Another way to do this is to break down your title using the PEO framework:

P = Population    E = Exposure    O = Outcome 

This works well where there is no comparison between two types of treatment or intervention.

In our example:

P = rheumatoid arthritis patients

E = mindfulness

O = health related quality of life

Other question formats are available such as PICO or SPIDER

Tip: Not all search topics will include every element of PICO – some include fewer items.

Once you have identified the key concepts, it’s important to think of any other terms or phrases that might have a very similar meaning. Including such synonyms will make your search as thorough as possible. For example, if your topic is looking for articles on Staff attitudes, you might also use the terms:

• Staff perceptions 
• Staff opinions
• Stereotyping
• Labelling 

If the database you are using has a list of subject headings, this may help you to find the most appropriate term for your subject. Some databases provide definitions for terms used in the database and may suggest related terms.

A comprehensive search will usually include both subject headings from databases and terms that you have thought of yourself.

Tip: Often your search term will be a phrase instead of a single word. To carry out phrase searches, use double quotes, for example “problem drinking”.

Once you have chosen your search terms, you need to think about the best databases for your topic. The databases you choose will depend on the search question and the libraries you have access to.

Tip: It’s well worth taking a few minutes to get to know the databases available on the Library webpages and what they cover.

The next step is to combine your search terms in such a way that you only retrieve the more relevant references for your search question. In order to do this you need to build a search strategy. This involves using Boolean operators such as AND, OR and NOT.

AND narrows the results of the search by ensuring that all the search terms are present in the results. 

OR broadens the results of the search by ensuring that any of the search terms are present in the results.

NOT limits the results by rejecting a particular search term. Be careful with NOT because it will exclude any results containing that search term regardless of whether other parts of the article might have been of interest.

OR will broaden your number of results while AND will produce fewer results.

Try using this Search-plan-worksheet to break your topic down into concepts. These can then be linked together when you run the search. You can also add synonyms within each concept box. The yellow limits box is a prompt to think about any limits you want to apply when searching. This leads us to Step 6.

Tip: Most databases will allow you to use a truncation sign (*) or wildcard (?) to pick up various different endings to words or alternative spellings.

For example:  alcohol* would pick up alcohol, alcoholic, alcoholism, etc

Sm?th would find Smith and Smyth

The next step is to think about any other restrictions you want to make to your results.

Common limiters found on databases include:

• By date
• Peer reviewed articles
• Research articles
• Age group (adult, child, older person)
• Document type

Not all databases allow all of the limiters above.

When writing a dissertation, primary research articles are normally required. Where the database allows you, try limiting to research articles only.

Non-research materials can also be useful as an overview of your topic; for example a literature review can give an analysis of what has already been written on a topic.

The video below includes a demonstration of how limits can be applied using the CINAHL database as an example:

CINAHL - advanced

Once you have identified all your search terms and any limits you want to apply, you are ready to run your search on the databases you have chosen. 

Once you have some search results, you can look through them and start to select those that look relevant to your literature search. It is likely you will reject some because they are not quite what you wanted but there will be others that can be marked for further attention.

The title of an article on its own may not tell you very much; read the abstract quite carefully to see if the article is relevant or not.

Tip: You can show more details for each record by clicking on the article title. On some databases, there may be an abstract for the article which you can open. 

If you find you are either generating more results than you can possibly look at or too few results to write about, be prepared to adjust your search terms and the way they are combined.

If you get too many results you could try:

•limiting to just the most recent material
•adding another term or concept and linking it using “AND”
•limiting to a particular country or geographical area such as UK

If you get too few results, you might try:

•expanding your date range
•removing any geographical limits you have applied 
•removing the least important term or concept

Tip: Be prepared to try other databases and keep searching until you feel confident you have found enough relevant material.

Once you have selected some articles that look relevant for your piece of work, you will need to save them so that your hard work is not wasted.

At the same time, you will want to save your search strategy. This is a record of the terms you searched, how you combined them, any limits you applied and how many results you found.

You will also need to choose a way to save your results. One way is to email the results to yourself and this can be done from all the databases.

Another way is to export your results to reference management software such as Zotero, RefWorks, EndNote or Mendeley. This software allows you to collect, organise and cite research. It is suitable for managing references over a long period of time. 

The RCN Library and Archive Service provides help with using Zotero. 

Tip: Keep a record of all the databases you use as you carry out your search. It is also a good idea to note where you found any references you subsequently use for your dissertation.

The final step is to obtain the full text of the articles identified in your search which you believe may be useful for your assignment. If you are lucky, many of these will be available electronically and you may just be able to follow a link to the full text.

Alternatively you can copy and paste your article title into the Library search box and if it is available as full text, a hyperlink will be shown which will link you to the document.

If you are studying elsewhere and have access to a university or hospital library, they may subscribe to different journals to the RCN Library so it is worth exploring what they can offer.

If your library does not have either an electronic copy or a physical copy, you may need to request the article by interlibrary loan.

Tip: It is also worth using Google or other browsers to check for the article title you require. Sometimes the article has been made freely available on the internet by the authors.

If after following these steps, you still can’t find what you are looking for, remember that there is always help available at your library. The RCN Library and Archives Service offers a range of help materials via our Literature searching and training pages.

These include:
• Databases guides in electronic and printed formats
• Video tutorials on how to search the databases
• 1-1 training sessions pre-bookable via the RCN website face to face or via zoom

A subject guide is also available on Doing your dissertation which provides suggestions for key resources, books and journal articles which may help. Click on the link below to access this guide:

Here are other resources you may also find helpful. You will find links to each resource below too:

• Aveyard H (2019) Doing a literature review in health and social care: a practical guide. 4th edn. London: Open University Press.
• Bettany-Satlikov J (2016) How to do a systematic literature review in nursing: a step-by-step guide. 2nd edn. Maidenhead: Open University Press.
• Coughlan M and Cronin P (2016) Doing a literature review in nursing, health and social care. 2nd edn. Los Angeles: Sage.
• De Brún C, Pearce-Smith N, Heneghan C, Perera R and Badenoch D (2014) Searching skills toolkit: finding the evidence. 2nd edn. Chichester: Wiley Blackwell / BMJ Books.
• Hewitt-Taylor J (2017) The essential guide to doing a health and social care literature review. London: Routledge.