Read the text in the text box 'Filters - limiting the number of search results'.
try a simple search in PubMed for leukemia[Title/Abstract]. Then use filters to limit the number of results to search results about children (0-18 years) and in the Dutch language.
How many results do you get now?
(click on the question to view the answer)
Read the text in the text box 'Clinical Queries'.
Perform a search within 'Clinical Queries' using the terms vaccination AND H1N1 and click on 'Search'. Next select at ‘Clinical Study Categories‘ the domain 'therapy' (this is the default setting), now select a sensitive search ('broad') and have a look at the number of hits. Do the same again, but this time with a specific search ('narrow'). For the same search you will now also see the systematic reviews. How many are there?
How many results do you get now?
(click on the question to see the answer)
If you get too many hits, despite the use of the right search terms, you can limit your search further via 'filters'. To do so you must first perform a search. Next you will see in the list of results a number of filters in the left hand side of the screen which you can click on (you can click on the image to make it bigger).
You can now set PubMed to only search for certain types of publications, or within a particular period. Via the option 'Additional filters', more filters are available, for instance for age groups ('Ages') or language (languages). You can also set a time period very easily by dragging the dots in the bar chart!
If you tick the box 'Journal' you can limit your search to articles in a subset of dental or nursing journals..
In general, be careful in the use of these filters: it often leads to a too strong limitation of your search results. Besides, in many cases you will lose the recent, not yet indexed articles. This is because most filters (with the exception of Languages and Publication dates!) are based on MeSH terms.
Please note: once you have set up filters, they will also be used in your next searches until you untick them.
A completely different way of searching is to use search filters offered by PubMed. Click on 'Clinical Queries' under 'FIND' on the homepage of PubMed. Mid 2020, you have to copy your whole search from legacy PubMed to the new interface. Simply typing a setnumber (e.g. #2) is not enough!
Only after entering the search you will be shown three different kinds of filters: 'Clinical Study Categories', 'Systematic Reviews' and 'Medical Genetics'. In this tutorial we will focus on the first two.
At 'Clinical Study Categories' you can indicate the kind of study you are interested in (etiology, diagnosis, therapy, prognosis, or clinical prediction guides). You can also indicate whether your search must be 'broad' (sensitive: many references of which a large part non-relevant) or 'narrow' (specific, fewer but more relevant articles, some relevant articles can be missed though). If you click on 'Filter information' at the bottom of the column you see how these filters are constructed.
Within 'Clinical Queries' you can also use a filter for 'Systematic Reviews'. As it turns out the terms 'review' and 'systematic review' may cause some confusion. A short explanation:
- Review: an overview article (does not necessarily have to be evidence-based)
- Systematic Review : overview of primary research articles using explicit and reproducible methods.
- Systematic Reviews (in PubMed): that particular part of the 30 million hits in PubMed that meet the search filter set up by NLM
Please note: Searching with filters is a quick way to limit the number of search results. However, using this search option also means that you rely on the ideas of others. Keep critically on whether the used filters are optimized for your particular query.
If you are looking for an article of which you know the data, for instance because you have seen the reference in a handbook or the article was recommended by your tutor, you can use the 'Single Citation Matcher' on the homepage of PubMed, under 'Find'.
In the 'Single Citation Matcher' you can enter the data of the publication. Often you only have to enter journal title, volume and page number: a useful tool if your reference is incomplete!