Literature searching

Literature searching is not a simple task. If the work is required for NHS work and/or NHS patient care please complete our request form and we can carry out the literature search on your behalf.

eLearning options

If you don’t have an opportunity to access our face to face or virtual learning or would like a reminder of what to do the following guide and short modules have been put together to guide you through the process.

NHS Health Education England e-learning options:

What Is A Literature Search?

A literature search is an important part of the research process, summarising current knowledge and informing future research. It should identify the amount and quality of work that has already been carried out in the topic area.

The key to a good literature search is planning – create a search strategy, much of which can be done before you log on to a computer. It can be time consuming but a properly constructed literature search will ultimately save time, helping the researcher avoid errors, identify validated instruments that could be used and highlight data analysis methods.

An important point for researchers to note is that literature reviews should be selective and critical; simply producing a list of works with no evidence that they have been evaluated or are relevant to the proposal is a waste of the researchers and reviewers time.

Before starting the literature search process a number of steps are recommended: –

1. Clarify the Question: You may need to consult textbooks to gain background information and understand a bit more about your topic. The first stage of any search is to clarify exactly what it is you are looking for. Write this down as a single sentence question or description of the information you would like to find. This question or sentence will form the basis for developing your strategy, so be quite specific.

2. Determine the search terms: Once you have your search question, you can start to break it down into search terms.

PICO may help you to break down your question:
• Patient /Population: the “Who”. For this you need to think of the patient group, clinical problem, age, sex,
ethnic origins or other defining characteristics of the patient and the population.
• Intervention: also sometimes known as exposure, and makes up the “What”. This is what is happening to the patient or population, so it could be a drug or a therapy, a screening questionnaire or a health improvement programme.
• Comparison: what the Intervention (or population) is being compared to. This could be a control group or another intervention.
• Outcomes: What outcome do you expect to see? For example, you may be interested in knowing whether an intervention has a health benefit, or whether an exposure results in mortality.

3. Choose the right database: You will probably need to use databases such as MEDLINE, CINAHL, Cochrane, Embase. etc.

Combining terms: Once the individual terms have been searched they can then be combined using the words AND or
OR. This will allow you to enhance your search by combining the search lines/terms in a number of different ways. This gives you the advantage of narrowing your search – if the initial search comes up with 1000+ ‘hits’, combining the search lines/terms allows you to narrow your search and make it easier to manage.

Limits: Searches can be limited in a number of ways – English language only; Study type e.g. randomised controlled trial; Date; Age group; Gender etc. The limits available will depend on the database you are using.