As a medical-legal consultant and Internet researcher I am asked every day to find authoritative medical literature
references for a broad spectrum of topics. The information I am looking for may be used to support a claim, to debunk an
expert theory, or to educate the attorney during the course of a case evaluation.
Changes in the way medical information is stored, accessed, and retrieved have created a wealth of health care
information. The Internet provides free access to a great deal of the medical literature, either in full text or citation/abstract
format. Because anyone with access to the Web can establish a Web page, many medical sites contain little useful
information, even though they may be visually appealing. For this reason, the quality of information available varies from
very good to poor, and some sites even intend to mislead. It is important to search for peer reviewed information, from an
I. Define The Search
Before you start your search, be clear as to the specific type of information you are seeking. It may be a standard of care
for a particular procedure, it may be the rate of occurrence for complications related to a specialized treatment, or it may be
basic information defining a disease or particular injury. You must identify the main concepts in your topic and determine
any synonyms, alternate spellings, or variant word forms for the concepts.
In order to define your search, you will need a grasp of basic medical terminology. The medical terms used in your search
usually come from records showing a diagnosis or particular treatment. The terms may include the name of a medication or
specialized medical equipment. It is a good idea to keep a medical dictionary and drug guidebook close at hand as
references, because spelling of medical terms must be accurate in order to get relevant search results.
Because the Web is not indexed in any standard manner, finding information can seem difficult. Search engines are
popular tools for locating web pages, but they often return thousands of results. Search engines crawl the Web and log the
words from the web pages they find in their databases. Without a clear search strategy, using a search engine is like
wandering aimlessly in the stacks of a library trying to find a particular book.
II. Performing the Search
Most of the major medical literature search sites have tutorials or help functions to assist you in customizing your search. It
may take some time to learn how to master the specific commands and options offered by the various search engines, but it
pays off by helping you avoid hundreds of hours fruitlessly searching.
Do not let the similarity between the appearance and function of medical search sites fool you into thinking they are all
alike. They are not. They use different rules and procedures to analyze your queries and decide what results are seen.
If you have tried a query a few times and are not getting the results you are looking for, switch to another search engine. It
is natural after searching for awhile to have "favorite" search sites. In one way this is good, the more you use a particular
site the more likely you are to master a particular tool. But, instead of relying on one search site for all your needs, try
using several different sites on a regular basis. This way you will get a feel for which ones work best for specific types of
searches. Over time, it will become automatic for you to select the "best" search site for each query from among the several
that you know well.
Boolean operators (and, or, not) allow you to construct very precise queries that theoretically should give you very precise
results. But this is not necessarily the case for two reasons. First search sites implement Boolean operators in slightly
different ways. If you are going to use Boolean operators, be sure you understand exactly how each site implements them.
Secondly, despite the apparent simplicity, Boolean logic is anything but simple. A misused "not" or a poorly "nested"
phrase can lead to wildly inappropriate results. For a good Boolean primer, with helpful illustrations and examples is
Boolean Searching on the Internet, from the University at Albany Libraries http://library.albany.edu/internet/boolean.html
Some search engines ignore certain words. They are never used to find a matching document, despite what amounts to a
direct command when you type them into a search form. These are called "stop words" because the search engine does not
"search" when they are found in its index. This is because the stop words are either too common to generate meaningful
results, or are parts of speech like adverbs, conjunctions, prepositions, or forms of "be" that mean nothing unless they are
part of a phrase with more "important" nouns and verbs. If you use a stop word in a query you may get wildly irrelevant
results. How can you identify stop words? They are listed at Most of the 300 Most Common Words in English
http://www.zingman.com/commonWords.html Some search engines will tell you when they are ignoring a stop word at
the very top of a results page.
Another problem for the net-searcher is whether to use capital letters in a query. Some engines are case sensitive, while
others are not. As a rule of thumb, it is best to always use lower case letters when you search This will typically return
results that contain both upper and lower case letters.
It is a good idea to bookmark or print out the information you find. It is easy to believe once you have found a page or site
using a search engine that you will find it again. It does not work that way. You may not get the same search results using
the same terms if you repeat a search within an hour, let alone days or weeks later. The Web is in constant flux. Thousand
of new pages are published to the Web every day, and thousands more moved to new "addresses", or are removed entirely.
This means a particular "relevance" of a particular document for a specific search query also changes constantly, as it is
compared to other documents added to or removed from the search engine index.
If you get stuck, and can not find what you are looking for on the Internet, do not stop looking. Sometimes your best bet for
finding information is to log off and take a trip to your local medical library. Libraries have many resources that are not
available on the Internet. And, the librarians are trained experts who are usually more than willing to help you find what
you are looking for. Effective searching requires a blend of learned skills, common sense, and a bit of clever intuition.
III. Where to Search For Medical Information
Medical Search Engines/Website Lists
Medical information on the Internet is growing and diversifying. Every month more information is added and it becomes
more challenging to sift through the many sites to find the content you are looking for. Traditional search engines do not
focus on medical sites, and therefore some very valuable sites are overlooked or not updated into the index.
To date, there is no all-inclusive engine for searching medical sites. Nor is there a single engine that adequately and
throughly indexes just the most reputable sites. These are a sampling of sites that will search for and retrieve up-to-date,
applicable and current postings from peer-reviewed sources.
National Library of Medicine
The NLM is a very large database and the efficiency of a search can be aided by a review of the MESH (medical subject
heading) "trees" at http://www.nlm.nih.gov/mesh/ The mesh trees incorporate the specialized language of the NLM
classification system. Failure to use the appropriate language will result in a null or irrelevant search. For example: the
phrase kidney calculi should be used instead of kidney stones.
Medline (accessible from various sites)
MEDLINE is the NLM's premier bibliographic database covering the fields of medicine, nursing, dentistry, veterinary
medicine, the health care system, and the preclinical sciences. MEDLINE contains bibliographic citations and author
abstracts from more than 4,300 biomedical journals published in the United States and 70 other countries. The file contains
over 11 million citations dating back to the mid-1960's. Coverage is worldwide, but most records are from
English-language sources or have English abstracts. Medline is free, and is accessible from various sites, such as
Medscape, Pubmed, and Healthgate..
The PubMed database was developed in conjunction with publishers of biomedical literature as a search tool for accessing literature citations and linking to full-text journal articles at web sites of participating publishers.
Publishers participating in PubMed electronically supply NLM with their citations prior to or at the time of publication. If
the publisher has a web site that offers full-text of its journals, PubMed provides links to that site, as well as sites to other
biological data, sequence centers, etc. User registration, a subscription fee, or some other type of fee may be required to
access the full-text of articles in some journals.
PubMed provides access to bibliographic information which includes MEDLINE as well as:
The out-of-scope citations (e.g., articles on plate tectonics or astrophysics) from certain MEDLINE journals, primarily
general science and chemistry journals, for which the life sciences articles are indexed for MEDLINE. Citations that
precede the date that a journal was selected for MEDLINE indexing. Some additional life science journals that submit full
text to PubMedCentral and receive a qualitative review by NLM.
Medscape is a multi-specialty Web service for clinician and consumers that combines information from journals, medical
news providers, medical education programs, and materials created for Medscape. Here you will find a combination of
peer-reviewed publications, a free version of drug information via the "First Data Bank File" and free Medline.
Healthfinder is a free gateway to reliable consumer health and human services information developed by the U.S.
Department of Health and Human Services. healthfinder can lead you to selected online publications, clearinghouses,
databases, web sites, support and self-help groups, as well as the government agencies and not-for-profit organizations that
produce reliable information for the public.
Founded by leading medical publishers that include Mosby and W.B. Saunders, MD Consult
integrates peer-reviewed resources from over 50 publishers, medical societies, and government
agencies. From this site you can obtain full text from 40 respected medical reference books from a variety of specialties, 50
medical journals, and MEDLINE. In addition you can obtain comprehensive USP drug information (beyond the scope of a
PDR), more than 600 clinical practice guidelines. This is not a free service, but for a small fee you can have access by the
day, month or year. Also there is a free seven day trial membership.
Medical Matrix is a source for a wide variety of online resources that include major journals, textbooks, disease and
conditions, and patient education. To access this site you must complete an online registration form.
Because it has few graphics, MedScout is very quick, yet it offers very broad and well-organized content. It also
conveniently lists diseases by International Classification of Diseases (ICD 9). Medscout indexes hundreds of medical web
sites. It supports its services by advertising and selling medical products.
Medical World Search
Medical World Search was especially developed for the medical field. Medical World Search can aid medical
practitioners, researchers, or anyone with basic knowledge of medicine, to formulate an optimally precise query to search
the World Wide Web and find exactly the information they need. The major goals of Medical World Search are to provide
a search engine that operates over a selection of the most high quality medical sites on the Web and to facilitate searching
by using a medical thesaurus that understands medical terminology and can thus search for related terms automatically.
This site is founded by academic physicians. Their goal is to make access to the Internet's vast health and medical
information as efficient and reliable as possible for healthcare professionals as well as consumers. MDchoice.com has
combined the content of several award-winning medical websites including NetMedicine.com, Physician's Choice, and
EMBBS.com (The Emergency Medicine and Primary Care Home Page). A panel of board certified physicians in the U.S.
evaluate the Web's medical content.
Achoo is a comprehensive health care database on the Internet with over 7000 indexed and searchable health care sites.
The site is organized by categories that include Human Life, Practice of Medicine, Business of Health, and What's New.
This site provides a comprehensive index of medical sites, but is mainly consumer focused and does omit a great deal of
the professional level content.
Guidelines Clearing House
This site is a public resource for evidence-based clinical practice guidelines. NGC is sponsored by the Agency for
Healthcare Research and Quality (formerly the Agency for Health Care Policy and Research) in partnership with the
American Medical Association and the American Association of Health Plans. A medical term search will retrieve
objective, detailed information on clinical practice guidelines. Results in a search will obtain: structured abstracts
(summaries) about the guideline and its development, a utility for comparing attributes of two or more guidelines in a
side-by-side comparison, syntheses of guidelines covering similar topics, highlighting areas of similarity and difference,
links to full-text guidelines, where available, and/or ordering information for print copies and, annotated bibliographies on
guideline development methodology, implementation, and use.
IV. General Information Searching
Search engines rely on computer programs called spiders or robots to crawl the Web and log the words on each page. With
a search engine, keywords related to a topic are typed into a search "box." The search engine scans its database and returns
a file with links to websites containing the word or words specified. Because these databases are very large, search engines
often return thousands of results. Without search strategies or techniques, finding what you need can be like finding a
needle in a haystack.
General search engines are good for finding information and sites on a specific topic. The search results generally will
contain many irrelevant sites, and you will need to "sift" through your results to find information that is useful.
There are many tutorials for web searching techniques on the Internet. One particularly good tutorial, which you may
download and print for reference is Bright Planet's "Deep Content" tutorial.
This is an in-depth Web searching tutorial, organized to proceed from the basics to more advanced topics. It has 12 parts
containing over 60 topics.
Listed below are some of the more popular general search engines.
General Information Search Engines/Website Lists
Google consistently turns up high-quality, highly relevant results. Google does well on specific queries such as American
Pediatric Neurological Organizations, and broad-topic searches, such as Medical Professional Organizations. It's also
great at targeting a specific home page. Depending on your query, you may get stock quotes, or related news stories for
example. My favorite feature is Google's ability to view cached copies of results pages. When the page you want to access
is no longer live, you can view a cached copy of the way it looked the last time Google crawled it. Google offers only basic
query customization features, including phrase searching and foreign-language filtering. You can use plus or minus signs
to include or exclude keywords, or you can head to the Advanced Search page for drop-down pick lists to construct
complex searches. There is a similar page" feature as well as a translator for foreign language websites.
About.com uses "professional Guides" to research and collect over a million useful sites in over 700 topic areas.
About.com is a great place to start a web inquiry as long as you're not looking for anything to specific. Think of it as a
resource library for popular subjects. Uses Sprinks (powered by the competent Inktomi) as a default search engine if it
can't find your query at about.com.
Dogpile uses a different concept to search the Internet than most other general content search engine. Rather than
maintaining its own database of Web site addresses and their contents, Dogpile searches the databases maintained by the
other general content search engines, such as Excite and Yahoo and Alta Vista, as well as databases maintained by Usenet
newsgroups, ftp sites, newswires, and business news sources. Dogpile begins by searching the larger general content
search engine databases and general purpose directories, and then gradually moves through smaller, more specific search
engines. The user is permitted to alter the order of search, however.
Open Directory Project
The goal of this new engine is to produce the most comprehensive directory of the web, Similar to Yahoo, listings are
organized by category and reviewed by editors. The ODP is a Web directory, not a search engine. Although they do offer a
search query, the purpose of the ODP is to list and categorize web sites. They do not rank, promote or optimize sites for search engines. The ODP is simply a data provider.
Created and maintained by P&S Koch of Oslo, Norway, Pandia Search Central aims to serve as a major search portal,
pooling a number of searching tools and guides. These include a metasearch engine that indexes AltaVista, HotBot, Yahoo,
Looksmart, Go Infoseek, GoTo, and WebCrawler at once; a news service and search engine; the Pandia Goalgetter, a
concise search tutorial; the Pandia Plus Directory, powered by the Open Directory Project; "Q-cards," which help users
form advanced queries on a number of selected search engines and directories; and a Pandia Sherlock plug-in for Mac
http://www.zdnet.com/ferret/download.htm (free download)
WebFerret is free software that searches the internet for you. (This type of program is called a "bot.") WebFerret uses
several search engines, looking as deeply as you like to "ferret" out the pages you're interested in. You can search the entire
text of pages, their titles and descriptions, just their titles, or even just their URLs. What you choose determines how fast
WebFerret works. In addition, WebFerret will eliminate duplicates by URL, title, or host. WebFerret will list the pages it
finds by relevance, title, address or source, then you can save your search as WebFerret search results (an ASCII file or
HTML). Since WebFerret is a small program, so it can work in the background.
The Internet continually offers more opportunities to find information on medical and related topics. However, with the
expanding resources comes a larger challenge for net-researchers to find the information they are seeking. The more
experience the researcher gains the more proficient they become in finding pertinent data.
Janabeth F. Evans, R.N., R.N.C. has a degree in Nursing from Oklahoma State University and a Litigation Paralegal Certificate from the University of Oklahoma Law Center. She was a nursing instructor for ten years and has been a medical legal consultant since 1990. Ms. Evans is currently President/Owner of Attorney's Medical Services, Inc. in Marshall, TX. In 2002 she was named the Association of Trial Lawyers of America's Paralegal of the Year. She provides litigation support for attorneys across the United States and specializes in case reviews and Internet information resources.
Her website is http://www.attorneysmedicalservices.com and her e-mail address is firstname.lastname@example.org.
Additional Internet Resources
www.acfas.org (foot and ankle)
www.fascrs.org (colon and rectal surgeons)
www.medicinenet.com (then click on dictionary)
www.4woman.org/nwhic/references/dictionary.htm (on line med dictionaries and journals)
Lage Listing of Medical-Related Sites