The Galter Library teaches a related class called PubMed. See our Classes schedule for the next available offering. If this class is not on our upcoming schedule, it is still available to you or your group by request.

PubMed, a service of the National Library of Medicine, includes over 19 million citations to biomedical journal articles dating back to the 1940s. The article citations are from MEDLINE and additional life science journals.

This guide describes some of the basic concepts of searching PubMed such as:

Choose PubMed from the Popular Resources menu on the Galter Library website to access PubMed. Accessing PubMed from the Galter Library website ensures that you will be using the Northwestern version of PubMed and will see links to full-text journal subscriptions through Galter.

Formulating a Subject Search

1. State your information need in the form of a question or a statement:

Example: Your 71 year old female patient recently had hip replacement surgery and has an increased risk for pulmonary embolism. You would like to compare the efficacy of coumadin and heparin to treat patients with an increased risk for recurrent pulmonary embolism.

Possible question: Is the anticoagulant coumadin more effective than heparin for treating patients with an increased risk of pulmonary embolism?

1. Break your question into individual, potential search terms: e.g. coumadin, heparin, pulmonary embolism.
2. Enter your search terms in the search box.  If all your search terms must be present in your results, use "AND" e.g. pulmonary embolism AND coumadin AND heparin. If any of your terms must be present, use "OR". However, use of the "AND" connector between search terms is optional. If you don't enter any connector the default is "AND".
3. Click Search.
4. Click on Advanced Search and apply Limits if applicable.
5. Evaluate the results to see if they answer your original question and refine the search if necessary. Hint: Click on Advanced Search and then Details to see how PubMed interpreted your search statement.

Use the MeSH Database to:

• Search for potential subject headings to help find the best term to use for a search.
• Select subheadings to refine your search further.
• Choose to restrict your search to Major Topic headings only.
• Build a PubMed search using the appropriate MeSH terms for your topic.

To build a search using the MeSH Database:

1. Choose MeSH Database under "More Resources".
2. Enter your first search concept.
3. Click Go.
4. A list of possible MeSH terms will appear or, if your search concept matches a MeSH term exactly, the detailed record for that MeSH term will display.
5. Click on the blue link for your preferred MeSH term to view the detailed record.
6. Select appropriate subheadings if desired.
7. Restrict retrieval to Major Topic headings if desired.
8. In the "Send To" pull down menu, choose either Search Box with AND or Search Box with OR.
9. Your search term(s) will appear in a new PubMed search box.
10. Repeat steps 2-8 to add more search terms and build your search.
11. When all of your search concepts are added click the Search PubMed button.

Among other things, you can use the advanced search to access your search history, review the details of your search (i.e. how your search terms were translated), apply limits to your search (e.g. English, Publication Date, etc.), and search by citation. To access the advanced search click on the Advanced Search link to the right of the main search window.

You can open and close different sections of the advanced search page using the "+" and "-" signs. Here is an example with only the search history open.

Use Details to:

• See exactly how PubMed searched the terms that you typed or selected
• Determine which MeSH terms can be used to describe your topic

To access Details, click on Advanced Search, then click on details.

You can apply limits to your searches using the Advanced Search. Limits filter your search results to retrieve only the results conforming to the chosen limits. Limits allow you to filter your search results by several criteria including:

• Publication type
• Language of article
• Age and gender of study subjects

The Clipboard feature enables you to:

• Temporarily save a list of article citations you select from various searches
• Sort the saved citations by Journal, Author or Publication Date
• Print, save, or e-mail the citation list

To save references to the Clipboard:

• Place a check in the box prior to the reference(s) you want to save
• Click "Send To"  and choose Clipboard

Your search history is available using the Advanced Search. The search history feature displays a numbered list of all searches performed allowing you to:

• View and access results from previous search sets
• Combine searches using set numbers (Remember, the connectors AND and OR must be capitalized when combining search phrases)

You can access the Journals Database under "More Resources". Use the Journals Database to:

• Find a journal’s title using its abbreviation
• Find a journal’s abbreviation from words in a journal title
• Find publisher information
• Launch a PubMed search for a journal

In the Advanced Search you can search by author, journal, and many other database fields using a quick and easy form. This is the easiest way to find an article for which you know all or part of the citation. A few key bits of information are often enough (e.g. author, journal, year) to find article citations. You can also search using a similar form by clicking Single Citation Matcher under "PubMed Tools".

The Clinical Queries section of PubMed (available under "PubMed Tools") allows you to apply quick filters or “hedges” to your searches. Search filters are available in several categories including therapy, diagnosis, etiology and prognosis. There is a broad filter and a specific filter for each category.

Clinical Queries:

• May be used with searches on therapy, diagnosis, etiology, or prognosis
• Uses filters based on the principles of evidence-based medicine to find articles most likely to be based on studies with sound methodologies

My NCBI allows you to:

• Save searches
• Set up e-mail alerts for new content
• Choose filters that group search results
• Create collections of saved references
• Set PubMed preferences

This page last updated Oct 2, 2009.