Literature searching and finding evidence

A more advanced way of searching than only using keywords is to use Subject Headings.

What are Subject Heading terms?

Each document within a database is categorised according to the topic(s) it covers and these categorisations are referred to as 'Subject Headings'.

Different databases use their own Subject Headings.

Medline and PubMed use 'MeSH terms': MeSH stands for 'Medical Subject Headings' and these are the terms created by the National Library of Medicine.

What is the advantage of using Subject Headings?

A Subject Heading search can be more precise than a keyword search as it will retrieve results where the focus of the study relates to the specific terms you enter.

For example, if you were looking for articles about 'strokes', a Subject Heading search will allow you to search for articles specifically on the medical condition: but a keyword search on its own might also pick up articles relating to 'pet therapy' or 'heat stroke'.

Searching using Subject Headings

As with a keyword search, you would need to search for Subject Headings related to each concept of your topic.

For example, for a topic on how exercise can reduce obesity in children, you would need to perform three separate Subject Heading searches on 'exercise', 'obesity' and 'children'.

Combining with a keyword search

For a more comprehensive search, combine a Subject Heading search with a keyword search. This is because:

• A study may have been categorised using different Subject Headings than the terms you used
• A Subject Heading may have been mistakenly left out of an article
• Subject Headings are different in each database, so you might not always find a relevant term to select.