Pre-Hospital Emergency Care OLD Sep 23: Introduction to Literature Searching

When you have a research question or topic you want to find relevant journal literature on, you will need to search subject-specific databases. Click on the Subject Resources tab to see the range of databases we have access to.

To search these databases effectively there are a number of search techniques you need to consider, including the use of synonyms and alternative terms, truncation, phrase searching and linking the search together with the appropriate Boolean operator/s (AND / OR). Also do you need to use a search history?

For more information on any of the techniques discussed on this page, please see Database Search Tips. 

Some databases also allow you to search what are called Subject Headings. 

A good way to explain Subject Headings is to think of them as tags or labels. It has been somebody's job to read the articles added to the database and to apply these tags to inform the user/researcher what the article is about, e.g. the context of the article. Two of the main health databases the library subscribes to which have such subject headings are CINAHL and Medline. On CINAHL they are called CINAHL Headings and on Medline they are called MESH Headings.

An example will better explain how searching such Subject Headings can be valuable. Imagine you are looking for literature on the condition of stroke. By searching on the word stroke as a keyword, results could be picked up which had nothing to do with the condition e.g. golf stroke, tennis stroke, stroke a dog; whereas if there was a subject heading for the condition of stroke such results would not be picked up.

Some databases assume that words typed next to each other should be searched as phrases. However, many databases do not do this.

Most academic databases automatically put a Boolean AND between your search terms: meaning that all the words used will be present in your search results, but they may not necessarily be next to each other. When this happens, your search results may not be relevant to your topic.

To avoid this happening, you can use "double quotation marks" to keep words together, and in the same order, when you search.

For example:

"airway management"

"out of hospital"

"high blood pressure" 

Further information on literature searching can be found in the guides below

To link a search strategy together there are two important words you need to use: AND and OR. 

These words are called Boolean operators. Another less frequently used Boolean operator and one which needs to be used with caution is NOT. This is used if you want to exclude a word/s from a search. For example, if you are retrieving studies conducted on animals but you want human studies, you would use the NOT operator followed by animals or animal testing. 

You use AND when you want to combine different topics together, and when you want both terms to be present in the resulting literature. For example, you are interested in the the airway management of emergency care patients:

When there are alternative words (aka synonyms) that can be used to explain the same thing e.g. high blood pressure, hypertension, elevated blood pressure; you link the words together using the Boolean operator OR to broaden out your search. This tells the database that any of your search terms can be present in the resulting literature:

One very useful technique that can be used on many databases is called truncation.

This is a technique that broadens your search to include various word endings and spellings. 

To use this technique, enter the root of a word and put the truncation symbol (normally an asterisk *) at the end.

For example:

therap* will find therapy, therapies, therapist, therapists, therapeutic

manag* will find manage, manages, managing, manager, management

mobil* will find mobile, mobility, mobilises, mobilizes, mobilisation, mobilization

child* will find child, children, childhood, childbirth