Idea: Arnold Leenders
Methodological Search Filters can help to narrow down a search by enriching for studies with a certain study design or methodology. PubMed has build-in methodological filters, the so called Clinical Queries for domains (like therapy and diagnosis) and for evidence based papers (like the“Systematic Review subset” in Pubmed). These searches are often useful to quickly find evidence on a topic or to perform a CAT (Critical Appraised Topic). More exhaustive searches require broader filters not incorporated in PubMed. (See Search Filters. 1. An Introduction.).
The Redesign of PubMed has made it more difficult to apply Clinical Queries after a search has been optimized. You can still go directly to the clinical queries (on the front page) and fill in some terms, but we rather advise to build the strategy first, check the terms and combine your search with filters afterwards.
Suppose you would like to find out whether spironolactone effectively reduces hirsutism in a female with PCOS (see 10+ 1 Pubmed Tips for Residents and their Instructors, Tip 9). You first check that the main concepts hirsutism and spironactone are o.k. (i.e. they map automatically with the correct MeSH). Applying the clinical queries at this stage would require you to scroll down the page each time you use them.
Instead you can use filters in My NCBI for that purpose. My NCBI is your (free) personal space for saving searches, results, PubMed preferences, for creating automatic email alerts and for creating Search Filters.
The My NCBI-option is at the upper right of the PubMed page. You first have to create a free account.
To activate or create filters, go to  My NCBI and click on  Search Filters.
Since our purpose is to make filters for PubMed, choose  PubMed from the list of NCBI-databases.
Under Frequently Requested Filters you find the most popular Limit options. You can choose any of the optional filters for future use. This works faster than searching for the appropriate limit each time. You can for instance use the filter for humans to exclude animals studies.
The Filters we are going to use are under “Browse Filters”, Subcategory Properties….
You can choose any filter you like. I choose the Systematic Review Filter (under Subsets) and the Therapy/Narrow Filter under Clinical Queries.
In addition you can add custom filters. For instance you might want to add a sensitive Cochrane RCT filter, if you perform broad searches. Click Custom Filters, give the filter a name and copy/paste the search string you want to use as filter.
Control via “Run Filter” if the Filter works (the number of hits are shown) and SAVE the filter.
Next you have to activate the filters you want to use. Note there is a limit of five 15 filters (including custom filters) that can be selected and listed in My Filters. [edited: July 5th, hattip Tanya Feddern-Bekcan]
Under My Filters you now see the Filters you have chosen or created.
From now on I can use these filters to limit my search. So lets go to my original search in “Advanced Search”. Unfiltered, search #3 (hirsutism AND spironolactone) has 197 hits.
When you click on the number of hits you arrive at the results page.
At the right are the filters with the number of results of your search combined with these filters (between brackets).
When you click at the Systematic Reviews link you see the 11 results, most of them very relevant. Filters (except the Custom Filters) can be appended to the search (and thus saved) by clicking the yellow + button.
Each time you do a search (and you’re logged in into My NCBI) the filtered results are automatically shown at the right.
Clinical Queries zijn vaak handig als je evidence zoekt of een CAT (Critical Appraised Topic) maakt. In de nieuwe versie van PubMed zijn de Clinical Queries echter moeilijker te vinden. Daarom is het handig om bepaalde ‘Clinical Queries’ op te nemen in ‘My NCBI’. Deze queries bevinden zich onder Browse Filters (mogelijkheid onder Search Filters)
Het is ook mogelijk speciale zoekfilters te creëeren, zoals b.v. het Cochrane highly sensitive filter voor RCT’s. Dit kan onder Custom Filters.
Controleer wel via ‘Run Filter” of het filter werkt en sla het daarna op.
Daarna moet je het filter nog activeren door het hokje aan te vinken. Dus je zou alle filters van de ‘Clinical study category’ kunnen opnemen en deze afhankelijk van het domein van de vraag kunnen activeren.
Zo heb je altijd alle filters bij de hand. De resultaten worden automatisch getoond (aan de rechterkant).
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