Topic-specific queries in PubMed are carefully constructed search strategies that can either be applied to a set of results as a filter or added to a search using ‘AND’.  Each of these searches has been created by an expert, tested to optimize sensitivity and specificity, and is periodically updated.  To view a complete list of the available searches, click the ‘Topic-Specific Queries’ link under PubMed Tools on the PubMed homepage.  This will bring you to the Directory of Topic-Specific PubMed Queries, where you can view the available subject searches, which include: AIDS, bioethics, cancer, health disparities, toxicology and veterinary medicine.  Clicking the link for a subject either limits your PubMed search to that subject area (i.e. applies a filter) or brings you to a page with the search strategy and additional resources.

Some of the searches can also be applied as filters from a search results page.  To do so, click the ‘Show additional filters’ link in the left-hand column of a PubMed search results page.  Check the box next to Subjects and click the Show button.  Select a link under Subjects to narrow your results.  If you do not see a particular filter, then click the ‘Customize’ link under Subjects to choose additional filters.  I don’t use topic-specific queries too often, but they can save you a lot of work if an appropriate search filter has been constructed for your topic.