How to find the best evidence.

The Internet has made finding evidence for clinical practice fairly easy. Many different types of databases that can be searched for relevant key terms are available for free or for subscription. Bibliographic or library databases contain books, book chapters, reports, citations, abstracts, and either the full text of the articles indexed or links to the full text. Citation databases are specially designed so that you can track the progress of an idea or research topic by searching the published works that cite a particular author or article. Synthesized databases are pre-filtered records for particular topics. They are usually subscription-based, with relatively large fees (but you can get free access in libraries). This type of database may provide the "best" evidence without extensive searches of standard bibliographic databases. Portals are Web pages that act as a starting point for using the Web or Web-based services and links to books, journals, patient-education resources, and images. Many medical journals, including Respiratory Care, are now available online. Finally, even generalized search engines such as Google, Yahoo, Ask, and Dogpile can provide a wealth of information on medical topics.