NUR 3300 - Foundations of Research and Evidence-Based Practice: Literature Search Help

When searching for individual research studies in healthcare, CINAHL and PubMed should be used. CINAHL is the major database for nursing and allied health literature.  PubMed is a way to search MEDLINE, the major database of literature in the biomedical sciences.

Google and Google Scholar are NOT sufficient for doing a good literature search in health care, although you can use Google Scholar to supplement your searches in subject specific databases.

Google Scholar alone is not sufficient for identifying evidence.

Search Examples for Boolean Logic

Boolean OR

When search terms are connected with OR, the search retrieves all the search terms used, regardless of whether all of them are found in the same article.  The colorized portion of this diagram represents all the search terms that would be retrieved.

More than one of the search terms may be in the same article, but even if only one of the terms is found in the source, it would  still be retrieved. For this reason, OR is often used to connect synonyms or related terms to make sure the search retrieves as many relevant sources as possible even if they did not use your original preferred term.

How this search would work in CINAHL:

"eating disorders" OR anorexia OR bulimia

Quotation marks are used to find eating disorders only as an exact phrase.

Boolean AND

When search terms are connected with AND, but ALL of the terms will be included in all of the articles or sources retrieved.  Notice that the shaded area representing retrieved results is much smaller for a search where all the terms are combined with AND, because it only retrieves sources that contain all 3 terms.  The shaded area of the Venn diagram represents only the cases where all 3 terms intersect or exist in the same source.

Although of these Boolean examples are too broad and retrieve many more results than you would expect to retrieve and review when searching for sources, notice that the number of results retrieved in CINAHL are considerably smaller when the same 3 search terms are ANDed together instead of combined with OR.

How this search would work in CINAHL:

"eating disorders" AND anorexia AND bulimia

Quotation marks are used to find eating disorders only as an exact phrase.

Combining AND and OR Boolean operators in one search

Often it is more effective to use both the AND and the OR connectors in a single search.

For instance, when searching a PICO question, there may be more than one term that is commonly used for a problem, intervention or outcome, so it is useful to OR all of those terms together.  For the search to work, it is necessarily to keep all the ORed terms separate from those being combined with AND.  Enclosing the ORs in parentheses is a good way to do this, as indicated below.  Note: Date and publication limiters have been applied to this search.

("eating disorders" OR "disordered eating" OR bulimia OR anorexia OR pica OR "night eating syndrome")

AND

(awareness OR mindfulness OR meditation)

AND

("self image" OR "body image" OR "self esteem" OR "self concept")

This video from EBSCO shows how to start searching CINAHL Subject Headings from scratch.  It does not use a PICO question example, but you can use the same process to identify subject headings for any of the keyword elements of your PICO(T) question.

Tutorial credit: U.S. National Library of Medicine

Tutorial credit: U.S. National Library of Medicine

This National Center for Biotechnology Information (NCBI) video demonstrates how to build a search from scratch using MeSH.  Although it is not a search on a PICO(T) question, the same process can be used to determine if there are relevant Medical Subject Headings for your population, intervention, comparison, and/or outcome.

Demonstrates ways to limit to specific types of research methodologies in PsycINFO.

These persistent links allow Wright State University users to access these articles through our subscription to AJN. Note: If off campus, you will be prompted for your campus w number and password before being taken to the article.

This collection of articles was authored by faculty from the Arizona State University College of Nursing and Health Innovation's Center for the Advancement of Evidence-Based Practice and published in the American Journal of Nursing (AJN)