Literature Searching: Guided Literature Search

Prepare to search the bibliographic databases by breaking your research question down into key components. The components are parts of your research question that should be present in any relevant article.   

With clinical questions, PICO can help you to identify the key components. PICO is an acronym that stands for:

In non-clinical questions, identify essential elements in your question.

EXAMPLES

LEARN MORE

Videos

• How to use PICO to refine your research question, MCW Libraries

• Searching Databases with Keywords, Lehman College Library

Reading

• Gallagher Ford L, Melnyk BM. The Underappreciated and Misunderstood PICOT Question: A Critical Step in the EBP Process. Worldviews Evid Based Nurs. 2019;16(6):422‐423. doi:10.1111/wvn.12408

Now that you have the elements identified, come up related keywords or synonyms that represent each topic. Not all authors use the same terminology, so try to think of different words that an author might use. Note that this is an iterative process. As you find relevant articles, you will discover additional keywords.

A chart can be useful to keep track of the keywords. As you find more keywords, add them to the chart. Note the “OR” between the keywords. OR is a Boolean operator and databases use Boolean operators to connect topics. 

Some ways to identify synonyms or related keywords:

• If your topic is something you don't know enough about yet, it can be hard to think of synonyms or examples.  Find some background information before starting your searching. (UpToDate, Wikipedia, Google Scholar are great general resources)
• Articles often include keywords under the abstract, look at those if you’ve already found a relevant article for your search
• Search the MeSH Database to find a relevant subject headings.
• Sometimes a specific intervention will be what the articles are using to describe their work (Example: “aroma therapy” instead of “non-pharmacological pain intervention”)
• Check a thesaurus for words you might be forgetting (thesaurus.com)
• Don’t forget about British or alternate spellings!

EXAMPLES

LEARN MORE

Video

• What is MeSH? MCW Libraries

Tutorial

• Medical Subject Headings (MeSH®) in MEDLINE®/PubMed®: A Tutorial, National Library of Medicine

With all the preparations in place, we are ready to search the databases. The library subscribes to and maintains links in over 70 databases, and each has its own scope and focus, and strengths and limitations. If you are searching for information related to medicine, medical education, healthcare, or biomedical sciences, PubMed is a good first choice. However, we recommend covering your bases by searching more than one source.

LEARN MORE

• Databases comparisons chart, MCW Libraries
  Featuring Google Scholar, CINAHL, Scopus, ClinicalKey, Ovid/MEDLINE
   
• Where to search for information | Infographic, MCW Libraries

Advanced searching in PubMed

Use the Advanced Search area to create your search in PubMed. Find a link to Advanced Search under the search box. 

Enter your search terms for each topic, one line at a time and combine the lines with "And." PubMed will add parentheses around each cluster of terms. 

Advanced searching in other databases

In databases like Web of Science, CINAHL and Scopus, your search lines can be entered line-by-line into the search boxes on the main page. 

TIPS

• As you AND together more topics, your search results will get smaller.

• As you OR together more synonyms, your search results will get bigger. 

• If you are using the PICO model, you may not want to include all the topics in your search. It may be helpful to omit the comparison or outcome topics. 

• Your initial search shouldn't be your final search. Play around with different combinations of words and topics to see what happens to your results. 

• Look for the Get It from MCW Libraries buttons to connect to the full text of articles. These can be found in most of our databases. 
  

CUSTOMIZE YOUR RESULTS

Results sorting

• PubMed's default sort is most relevant but it can be changed to most recent by changing the display options.

Filters

• Most databases offer filters on the left-side of the results page that can be used to limit to fields such as publication types, language, and year of publication.

• PubMed also has additional filters for age, sex, subject, etc. 

LEARN MORE

Videos

• PubMed® Online Training, National Library of Medicine

• Conducting a Literature Search Using PubMed, MCW Libraries. This video features the legacy PubMed platform, but the principles are the same.