Edward & Barbara Netter Library
For Medicine, Nursing, & Health Sciences
For Medicine, Nursing, & Health Sciences
When you have a simple search, just 2 or 3 keywords, you can use Basic search box on PubMed homepage.
When you have a complex search (more than one keywords for each concept), we’ll use PubMed Advanced Search Builder.
Take PubMed's “All Fields” option as an example. When you search in All Fields, PubMed applies Auto Term Mapping, which automatically includes word variations and MeSH terms in your query. This ensures you retrieve the broadest set of relevant results. If you want to narrow your search, you can select Title/Abstract field, apply filters or visit Revise and Refine Searches for additional tips. See an example below:
1. Identify key concepts
For clinical questions, PICO framework can help you to identify the main concepts. For general research questions or when PICO doesn't apply, find the nouns in your research question, then pick the key concepts. As most often, concepts are nouns. In addition, thinking about what key concepts the articles should include in the search results.
2. Collect search terms
When collecting search terms, include keywords, alternative terms that authors might use to describe the same concept. List them in your concept table. Use Boolean OR to combine alternative terms for the same concept. If your search includes a phrase, enclose the entire phrase in parentheses.
Note: For this example question, I did not include any specific outcome terms in the search because I want to review all possible outcomes. If you have particular outcomes you’re interested in, you can include them in your search. For instance, if you want to examine the effect of a medication on body weight, search for body weight rather than increase body weight.
3. Search each concept separately.
4. Combine concepts.
After completing searches for all your concepts, combine them using the Boolean operator AND. On the PubMed Search Builder page, click the three dots under Actions for your first concept and select Add query. This will add the concept to the query box. Next, click the three dots under Actions for your second concept and choose Add with AND to include it in the search. Repeat this process for each additional concept until all are combined.
After adding all the concepts, the complete search query will appear in the query box. Once you click Search, you can also view the query in the search box on the results page.
Note: Avoid writing the search query manually, as it’s easy to make mistakes. Instead, use the PubMed Search Builder to generate the query automatically.
5. Apply filters.
Use filters such as age, gender, or study type as needed. In PubMed, for example, you’ll find filters like systematic reviews, randomized controlled trials (RCTs), and observational studies under the 'Article Type' filter.
Keywords, also known as search terms are the words that you enter into database search boxes. They represent the main concepts of your research project.
Keywords summarized:
When searching in databases, keywords can be used to...
Searching is an iterative process that will take trial and error. Be patient -- you'll find the right words to use.
Note. From Diagram Explaining Boolean Operators, by Cecelia Vetter, 2021, Wikimedia Commons
(https://commons.wikimedia.org/wiki/File:Diagram_Explaining_Boolean_Operators.png). CC BY-SA 4.0.
Phrase searching includes placing quotation marks ("__") around two or more words to create a search term. This searching technique dictates to the database to retrieve only those results in which the exact phrase appears.
A search for attention deficit disorder = attention AND deficit AND disorder -- without phrase searching
A search for "attention deficit disorder" = "attention deficit disorder" -- with phrase searching
Note: Phrase searching in individual databases may vary. Check the help pages in each database for additional information.
Consider using synonyms and abbreviations to enhance your searching. The English language is filled with many different ways of saying the same thing. Using synonyms and abbreviations while searching in databases will help ensure that you are able to create a comprehensive search string that will capture all relevant articles.
Synonyms are words that have the same or similar meaning to another word or phrase. Many concepts have different terms that can be used to describe them. For example, some additional keywords that can be used for Pediatric Obesity include:
If you are not sure how to find synonyms for your terms, try looking in PubMed's MeSH (medical subject headings) database. Most entries in the MeSH database include a list of 'Entry Terms'. These are all the terms that you could search that would be still ultimately connect to a specific MeSH term in PubMed.
When searching, you should always spell out any abbreviations that might be included among your search terms. For example, if yoy are searching for articles on PTSD, you should spell out the phrase, post-traumatic stress disorder, as well as include the abbreviation.
Truncation, also called stemming, is a technique that broadens your search to include various word endings and spellings.
Child* = child, child's, childhood, children, children's,
Some important things to note about truncation:
If I searched toxic* in PubMed, my search results would include....
Wildcards are another searching technique. They are used in search terms to represent one or more other characters.
