Activating a filter will narrow your search results, e.g., you may filter your search results to Clinical Trials and articles published in the last 10 year. A "Filters activated" message will display on the result page.
To turn off filters, click either the “Clear all” link to remove all the filters, the “clear” link next to a filter category to clear the selections within that category, or the individual filter.
Only valid filter options for a result set will display on the sidebar, e.g., Meta-Analysis was removed from the filter list in the search above because none of the result citations were tagged with that article type.
To add additional filter categories to the sidebar, click the “Choose additional filters” link at the top of the filters sidebar.
Select the desired filters, and click "Show." This will add them to the sidebar. You will need to click on them in the sidebar to actually apply them to your search.