Finding Health Information on the Web
http://www.healthysf.org/searching.html | Brian Katcher, PharmD

There are two major problems in using the Web to find health-related information:

1. Health information on the Web varies in quality. Anyone can post health information on the Web. The Medical Library Association has compiled a list of questions that you might ask when looking at a Web page. Remember, a professional-looking page is no guarantee that the content will be useful. (http://www.mlahq.org/resources/medspeak/meddiaq.html)

Some pharmaceutical companies have created authoritative-looking Web sites that serve as vehicles for promoting their products, or as a means for competing with other sources for information. For example, cancer.com is owned by Johnson & Johnson -- cancer.com (which contains advertising for Johnson & Johnson) might easily be confused with cancer.gov (NIH) or cancer.org (American Cancer Society)

2. Important health information is difficult to find. There's lots of health-related information on the Web, and only a small portion of it is organized in any cohesive fashion.

Here are some useful links, organized by category:

Search Engines

Search engines look at all the words on a Web page, as well as the links to and from the Web page (and, in some cases, additional criteria) for determining its ranking in response to a query. The ranking of "hits" from a search may or may not be suitable to your needs. Specific sites are easy to find, if you know their names. A lot of important health information is invisible to search engines. Only a very small portion of the Web is carefully indexed (the National Library of Medicine's work, an important exception, will be discussed later).

Google (http://www.google.com) -- Editor's choice! In addition to its well-known main search page, Google offers some specialized pages that may be of value for health professionals: Following the "Images" link above Google's main search box will take you to Google Image Search, where you can find images to use in your PowerPoint presentations. Following the "more" link above link above Google's main search box will take you to a page that has a link to many Google services, including Scholar (http://scholar.google.com). Scholar uses Google's search algorithm, in which number and quality of links help to rank a page, but its results are limited to articles and books of scholarly interest. In some instances, you there are links to articles that cited the paper you are looking at. Very useful!

Suggestion for in-depth searching in Google Scholar: Searches for health information in Scholar will often point to PubMed citations, or to abstracts/articles that are indexed in PubMed. When you find useful articles in Scholar, determine how they were indexed for PubMed - MEDLINE (MeSH terms), and do another search in PubMed using these terms. Why? Because of the way that Scholar ranks hits, it can miss the latest papers, and -- more importantly -- it lacks PubMed's ability to conduct Boolean searches based on the concepts that are represented by MeSH terms. But starting with Scholar can help you to think about what concepts you are interested in.

Scirus limits its results to scientific information. Its default mode searches both journals and the web, and its results page provides a link to each search. Less well known than Google Scholar, this is a powerful tool. Highly recommended.

Yahoo! Search (http://search.yahoo.com)

MSN Search (http://search.msn.com)

Selected Public Health Sites of Great Value

Centers for Disease Control and Prevention -- The CDC, which is part of the U.S. Dept of Health and Human Services, is arguably the largest public health agency on the planet. (It has twice as many staff as the World Health Organization.) As you might expect, the CDC site is huge; it's really many Web sites. Take some time to explore it. (http://www.cdc.gov)

The Disease Control Priorities Project, provides a comprehensive approach to assessing disease burden, including risk factors, and summarizing the best evidence about inteventions. (http://www.dcp2.org/main/Home.html)

The Guide to Community Preventive Services provides CDC-funded evidence-based reviews of interventions for common public health problems. (http://www.thecommunityguide.org/)

Surgeon General Reports -- Authoritative reports on important public health issues. (http://www.surgeongeneral.gov/library/reports.htm)

Healthy People 2010 -- National health promotion and disease prevention goals and objectives for us to attain by the year 2010! The entire document is on-line & can be viewed in portions...follow the "Publications" link to see links to the full text of the document. (http://www.health.gov/healthypeople/)

Partners in Information Access for the Public Health Workforce -- A collaboration among a variety of professional organizations (e.g.,APHA, SOPHE) and governmental agencies (e.g., CDC, HRSA, NLM). (http://phpartners.org)

San Francisco Department of Public Health (http://www.sfdph.org/dph/default.asp)

What about Wikipedia? (http://www.wikipedia.org)

HealthySF.org (http://www.healthysf.org) -- Well, maybe not of great value yet, but it's unique, and it's local.

Libraries

Librarians are experts in the organization of intellectual resources (historically, this has been books), so it is not surprising that medical librarians have made significant attempts at organizing medical information on the Web.

University Health Sciences Libraries

Hardin MD (http://www.lib.uiowa.edu/hardin/md/az/az.html) is a directory of directories, organized by topic areas. Links to more links. Compiled by Eric Rumsey at the Hardin Library for the Health Sciences at the University of Iowa -- a very rich site.

The Recommended Core Collection of Web Sites for Hospital Libraries, created by the Camden Campus Library of the University of Medicine & Dentistry of New Jersey, is another useful list of links.

UCSF Library (http://www.library.ucsf.edu/) has links to many University of California San Francisco resources (some of which require a campus affiliation for Web access but all of which are available from the library). The library itself a great non-virtual location if you're in San Francisco. [Take the N-Judah streetcar to UCSF (from Civic Center) (from Van Ness)] Also in San Francisco, and affiliated with UCSF is the Barnett-Briggs Medical Library at San Francisco General Hospital -- their page of local SF resources is quite good.

National Library of Medicine

The National Library of Medicine (NLM) is the word's largest medical library. The scope and depth of its work -- and its Web pages -- are correspondingly grand. (http://www.nlm.nih.gov/) Here are some key locations within this huge site:

Full list of resources at NLM

PubMed/MEDLINE - bibliographic information about biomedical journal articles (includes abstracts and links to full text) ... this highly structured bibliographic database will be discussed separately (see MEDLINE).

Medlineplus - nontechnical information aimed at the general public (but also very helpful for health professionals)

MEDLINE

MEDLINE is the National Library of Medicine's (NLM's) on-line index to articles that have been published in health-related journals during the past third of a century. It is the oldest and most comprehensive biomedical electronic resource. As such, it is an important resource for health professionals. MEDLINE has many interfaces, but it's best to start with the National Library of Medicine's PubMed (http://www.ncbi.nlm.nih.gov/PubMed/).

MEDLINE is a highly structured bibliographic database. It works best when you search with Medical Subject Headings (MeSH), such as asthma, blacks, hypertension ... use the MeSH Database on the left-hand side of screen of PubMed to find the MeSH terms that best describe the concepts you will be searching under. (The MeSH Database's animated tutorials don't take long to complete.) You can build searches within the MeSH Browser or enter these MeSH terms in the query box (words that are typed into the default query box are automatically "mapped" to MeSH, journal names, and author names). You can also use the "Limits" feature to limit to a specific publication type (such as review article, practice guideline, or randomized controlled study), a specific age group, or a subset of journals.

Although many citations include abstracts, you may need to go to a medical library to read the full article. When you see articles that seem particularly useful in PubMed, follow the link to "related articles," which are related by the words in the titles & abstracts and the MeSH terms that were assigned to these articles. The "related articles" link is a very powerful feature.

Some journals offer free full text articles on the web. The NLM created PubMed Central to serve as a digital archive of such articles. PubMed search results that are available at PubMed Central bear a distinct link.

Before you begin searching in MEDLINE, make sure you can't answer your question by looking in a book or a Web page that is aimed at your needs. (Note that the NLM's Bookshelf of full text books includes guidelines for common medical problems, and the huge Health Services/Technology Assessment Text (HSTAT), which includes evidence-based reports.) MEDLINE is the place to go when you want to answer a question by carefully researching the primary literature.

PubMed searching takes some time (on average, 30 minutes per search). With practice, your searches will improve.

Medline-related resources (on-line appendix from a book about PubMed/MEDLINE)

U.S. Government

The Department of Health and Human Services is the overall government agency for health. Its Web site is designed for the general public. However, it also contains links to the various NIH institutes and centers, the Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), the Agency for Healthcare Research and Quality HRQ), and other U.S. Government health agency Web sites.

More Information

The National Library of Medicine's MedlinePlus has a useful page of links, entitled Evaluating Health Information (http://www.nlm.nih.gov/medlineplus/evaluatinghealthinformation.html). In addition, the National Library of Medicine recently created a tutorial (approx 16 minutes long) on this subject.

The Medical Library Association (MLA) has produced a User's Guide to Finding and Evaluating Health Information on the Web (http://www.mlanet.org/resources/userguide.html), which includes a list of their "top ten" most useful consumer web sites. Also of note for consumers, the MLA has produced Deciphering Medspeak, a collection of resources to help decipher the technical language used to describe medical issues.

This page is intended as a resource for a two hour class that is given regularly at the San Francisco Department of Public Health's Health Education Training Center. This is a broad overview, not a comprehensive list. On the other hand, the links from these selected links are likely to take you to where you want to go. For comments, questions, suggestions, contact Brian Katcher.
This page was updated on April 9, 2009.

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