Searching for focussed and targeted evidence
Do you need to find answers to your research question quickly? Do you want to retrieve a smaller number of results that are targeted to your research question? Do you want to identify higher quality evidence from the vast amount of literature available?
If you answered ‘YES!’ to any of these questions, then there are some tips below from our Information specialists that may be able to help you:
Medical Subject Headings (MeSH) used in Medline, and Emtree headings used in Embase, are controlled and hierarchically organised vocabularies used for the indexing, organising, and searching of biomedical and health-related evidence. These headings make it easier to search for evidence and allow you the option to explode or focus. Exploding allows you to retrieve results using the selected heading and all its more specific terms. Focussing allows you to limit your search to the evidence in which your subject heading is considered the major point of the article.
a. In Medline, type your keyword into the search box. The below example shows ‘diabetes mellitus’. Check the box next to Map Term to Subject Heading, and then Search.
b. On the next page, your keyword is matched to the subject heading, ‘Diabetes Mellitus’. Next to it are boxes for Explode and Focus. Check the box next to Focus, click Continue, and then Continue again on the next Subheadings page.
c. In the search history below, line 1 shows that focussing ‘Diabetes Mellitus’ retrieves 90,640 results. Exploding ‘Diabetes Mellitus’, in line 2, retrieves 470,660 results. Focussing is good search technique to use if you want to retrieve a smaller and targeted set of results.
In Medline and Embase, you can instruct the database to search for your own keyword search terms in several different fields by using two-letter abbreviations. You can find out more here.
For example, searching for ‘diabetes mellitus.mp’ instructs the database to perform a Multipurpose search which searches for ‘diabetes mellitus’ across a number of different fields simultaneously. However, if you want to retrieve something more targeted you could, for example, search for ‘diabetes mellitus.ti’, which instructs the database to just look for your keyword in the title of the article.
In line 3, we retrieved 485,884 results by performing a Multipurpose search. In line 4, we retrieved 79,664 results by performing a Title only search.
If you need any support or assistance in using Medline and Embase, please book onto an assisted search session where you have the opportunity to discuss your research question with an information specialist, or a search training session where you can learn techniques for carrying out your own searches.