Medline: Navigating the Maze

What is MEDLINE

The National Library of Medicine produces the MEDLINE database. It is
widely recognized as the premier source for bibliographic and abstract
coverage of the biomedical literature. It indexes more than 11 million
article records from more than 4,600 journals.

STRENGTHS: Despite the proliferation of new evidence-based medicine
information sources, there is still a need to know how to search MEDLINE
efficiently. There will be many times when EBM-specific databases will
not locate the information you need. MEDLINE's strengths include its large
size, currency of the information (Pre-MEDLINE), coverage of the non-therapeutic
literature, and historical information.

WEAKNESSES: The MEDLINE search interface is more powerful than most
databases, but search techniques and filters need to be learned for efficient
searching. It is also more time consuming to use, because the burden of
analyzing and interpreting the article's relevance to clinical care is
up to the searcher. It may be necessary to read an entire article before
evaluating its usefulness in decision-making and application in the patient
care setting.

Searching MEDLINE

The best way to achieve good search results in MEDLINE is to use a search
strategy that takes advantage of the wonderful controlled vocabulary of Medical Subject Headings (MeSH), subheadings that are pre-assigned to each MeSH term, and the ability
to limit subject search results further by publication
type (e.g., meta-analysis) and/or methodology (e.g., clinical trials).

Textword searching (also known as Keyword Searching) is another way
to search MEDLINE without the use of the controlled subject headings (MeSH).
Textword searches look for the word or words in the Title and/or Abstract
fields of the MEDLINE record. Textword searching works best when there
is not an appropriate subject heading that describes your specific search
concept. Textword searches only find matches on the exact word(s) you
type in; so you will want to truncate the word as appropriate to broaden
your possible retrieval.

For example, there is not a MeSH term for the concept predisposition.
So when doing searches on the etiological aspect of a condition, you may
want to search predispos$" (the $ or : can be used to truncate)
as a textword. This would locate articles that have the words predisposition
or predispose or predisposed in the titles or abstracts.

For help in searching Ovid's
version of MEDLINE, please see UVa's guide, "MEDLINE:
The Magnificant 7 Search Steps" (PDF).

PubMed

The National Library of Medicine (NLM) creates the MEDLINE database,
but there are several search interfaces to MEDLINE available from commercial
vendors, such as Ovid and MD Consult. MEDLINE/PubMed and MEDLINEplus are
two of NLM's own free search interfaces to the MEDLINE database and other
sources of government information.

In addition to including PREMEDLINE (a segment of MEDLINE that provides
basic citation information and abstracts before the full records are prepared
and added to MEDLINE), PubMed also offers searchers the opportunity to
apply proven clinical filters to their searches. These clinical filters are a way
to reduce search retrieval to articles relating to four types of clinical
research - diagnosis, etiology, therapy and prognosis. There are also
options to direct the emphasis of your search to be more sensitive or
more specific. Another nice feature of PubMed is the ability to link
to Related Articles.

For help in searching PubMed, please see NLM's excellent "how-to" PubMed Tutorial .

To try Ovid's version of MEDLINE, go to http://gateway.ovid.com and enter:


ID = uvademo

PASSWORD = knowhow


This Free code is courtesy of Ovid Technologies, and will be active
through April 24th, 2003.