Formulating a strong clinical question is the first step in the research process. PICO is a way of building clinical research questions that allow you to focus your research, and to create a query that better matches most medical databases.
Example: In a (describe patient) can (intervention A) affect (outcome) compared with (intervention B)?
On the front page of many databases you have the opportunity to select options to make your search smaller before you begin. Limiters may include:
Click here to see an example of the pre-limits in Medline.
After you have run a search, you can add precision to your results by using the filters (frequently found on the left side of the screen.) Filters may include:
Click here to see an example of CINAHL's filters.
You can also re-sort your results based on Relevance, Date, and other options.
Many databases allow you to combine multiple searches for added precision. In MEDLINE and CINAHL look for "Search History" to use this feature. Click on View Results to see the results from each search.
In Cochrane, use the "Search Manager" feature. Click on the number on the right to see the results from that search.