Subject search results can be limited by study types to locate research based on level of evidence. Below are tips for utilizing "limits"or "filters" for the following databases:
To limit your subject search results by research study types, in the Search Options section in the Basic or Advanced search, find the “Publication Type” limit, and select the desired type of study, such as Clinical Trial, Randomized Controlled Trial or Systematic Review. Hold down the “Ctrl” key to select more than one publication type. Once you have selected the desired publication types, click Search.
For study types that are not listed in the “Publication Type” limit box, search the “CINAHL Headings” for the study type. For example, search for Prospective Studies (also called cohort studies) as a CINAHL heading, and use the AND operator to combine this set of results with your topic search result.
To limit your subject search results by research study types, at the top of the left margin of your search results, under Article Types, click the type of study you want to find. If the desired type of study is not displayed, click "Customize" and choose from the resulting list all the study types you would like to display as available filters, then click "Show", and the selected study types will display in the left margin.
Click each type of study you would like included in your in your results, holding down the Control key to select more than one type. Note: "Clinical Trial" will include all individual phases of clinical trials, and will also include Randomized Controlled Trials.
For study types that are not listed as Article Types, like "cohort studies" or "longitudinal studies," search these terms as MeSH terms, and use the AND operator to combine with your topic search results.