MEDLINE-Related Resources

MEDLINE from the National Library of Medicine (NLM)

Other Interfaces to MEDLINE

Medical Subject Headings (MeSH)

MEDLINE Tutorials

In-Process Citations in PubMed

Journals on the Web

NLM Resources

Health Information on the Web

This page is based on an appendix from Katcher BS. MEDLINE: a guide to effective searching in PubMed and other interfaces. 2nd ed. San Francisco: Ashbury Press; 2006.

MEDLINE from the National Library of Medicine (NLM)

The National Library of Medicine, which produces MEDLINE and licenses it to other vendors, provides free access on its Web site:

PubMed. If you are not already using MEDLINE, PubMed is the best place to start (unless you are starting out at an academic institution that uses Ovid). PubMed is very fast, easy to use, and has excellent on-line MeSH help. PubMed provides context-specific links to other Entrez databases and to resources beyond the National Library of Medicine. Among experienced searchers not using a particular university-based MEDLINE interface such as Ovid, PubMed has become the de facto standard.

PubMed is MEDLINE with additional citations that have not yet been indexed for MEDLINE or are beyond its scope, as well as citations from OLDMEDLINE (pre-1966 citations). An NLM Fact Sheet explains the difference between MEDLINE and PubMed.

For serious searches in any MEDLINE interface, you will want to give some thought to the MeSH that best describe the concepts you are researching, and PubMed's MeSH Database is particularly helpful in this regard. In fact, you can even construct your search strategy from within this well-designed MeSH Database, which can be reached from a link on the left side of the PubMed home page. PubMed's Citation Display contains links from the MeSH terms assigned to each article; these can be used to find more information, or they can be used as the basis for a new search strategy.

The limits options in PubMed allow you to restrict your searches by Publication Type (such as Clinical Trial, Meta-Analysis, Practice Guideline, Review, or Randomized Controlled Trial), language, subsets (such as Abridged Index Medicus, Complementary Medicine, Nursing, Dental, or AIDS), and other elements that are built into MEDLINE.

PubMed's Clinical Queries and Special Queries filters provide a handy means for starting a search. After an initial search, you will probably want to construct additional search strategies based on what you have learned.

After you have done a search, use the "Details" tab to see how PubMed has processed your search. For more information about each element, see PubMed Help or NLM's more detailed MEDLINE/PubMed Data Element Descriptions information page.

To get the most out of this interface, take a look at PubMed’s Tutorial (linked from the PubMed home page).

Gateway. NLM Gateway is intended for users who come to the National Library of Medicine without knowing what is there or how best to search for it. NLM Gateway provides a single interface for searching in a number of the Library’s resources, including PubMed, MedlinePlus (described below, under “Health Information on the Web”), the NLM Catalog, ClinicalTrials.gov, DIRLINE (Directory of Health Organizations), and others. NLM Gateway's most remarkable feature is that it searches simultaneously within multiple retrieval systems. Its Find Terms button leads you to information about the Medical Subject Headings (MeSH) that might encompass the terms you enter.

If you know that what you are looking for is in MEDLINE, then PubMed is a more appropriate interface, because its limits feature is specific to MEDLINE. (The limits button in the NLM Gateway is for categories, such as journal articles, consumer health, books/serials/AV, or databanks.) However, NLM Gateway provides access to much more information than can be found in MEDLINE. A full description of what's available from NLM Gateway can be found on its "About" page.