The Internet as an evidence-based medicine tool

Issue: BCMJ, vol. 46 , No. 6 , July August 2004 , Pages 282-284 Clinical Articles

The Internet makes numerous information resources available, many of which support evidence-based medicine: journal articles, structured abstracts, systematic reviews, clinical practice guidelines, and aggregated resources. The Internet is also changing scientific publishing and facilitating the development of consumer health informatics and bioinformatics. This abundance of information is a mixed blessing that requires clinicians to learn more about the resources available and how best to use them.

Clinicians can find answers to specific questions and update their understanding of a topic through the information services provided by many organizations, including the National Library of Medicine, the Canadian Medical Association, the BC College’s Medical Library Service, and the UBC Library.

The use of the Internet as an evidence-based medicine (EBM) tool is very recent. For many years there has been a predictable chain of events in scientific communication. Research is reported in papers presented at scientific meetings and published in conference proceedings and peer-reviewed journals. These publications are then indexed in a bibliographic index such as MEDLINE (Index Medicus online), which in turn leads to the information being discussed in review articles and included in textbooks. Typically, clinicians can rely on the meetings, journals, indexes, and books that represent their field of interest to support their management of patients. However, with the never-ending flow of new information provided by improved publishing and information technologies, it has become difficult to keep up.

Since the 1990s, the Internet has been affecting both the accessibility and the types of information available to clinicians. Much of this information—whether in the form of books, journals, indexes, or conference proceedings—is now available by computer from any networked location. And because the Internet has made it so much easier to distribute many different types of information, publishing can now be done by scientific societies, commercial ventures, and any group or individual who wishes to share information. This is having an impact on the quality of information and raises the question: Is the information we retrieve of good quality, peer-reviewed, and complete?

Some critics suggest that there is now a blurring between the functions in the traditional flow of scientific communication.[1] One example of this is that a publisher with control of numerous electronic journals can allow users to search a collection of journal articles in the way one might search an index such as MEDLINE. The difference here is subtle but significant: when searching a publisher’s collection of journals you may cover many subject areas but you are seeing the offerings of just one publisher; when searching with the help of an index you are seeing the offerings of a wide variety of publishers.

For busy practising physicians, the increased access to information is useful, but it is also a mixed blessing. Access may have increased, but the problem of too much information is compounded. The complexity of the information world has grown along with the ease of access, making it far more important for clinicians to understand the information sources available on the Internet. Understanding what is available and what each resource can do for the user makes it possible to find the right information efficiently.

Information available on the Internet

One of the most important considerations in choosing an information resource, whether print or electronic, is the type of information needed. Asking a specific question about an individual patient’s case will lead to a different resource than asking a general question in order to keep up-to-date on a topic. It is important to consider the different categories of information available.

Journal articles and indexes

Journal articles are by far the most-used resource. Finding an article on a chosen topic is still most efficiently done using an index such as MEDLINE, searched through OVID or PubMed. As mentioned, the advantage of using an index is that it covers a large number of journals from a variety of publishers. For those unfamiliar with searching MEDLINE, there is a useful tutorial at

Structured abstracts

Structured abstracts provide access to brief synthesized information. The abstracts contain key information from articles on RCTs published in core clinical journals. Typically, the structured abstract and the accompanying commentary by a subject expert are about one page long. Publications containing structured abstracts include ACP Journal Club ( and Evidence-Based Medicine (, both of which are available to subscribers.

Systematic reviews

Where structured abstracts provide details and interpretation of one article’s findings, review articles summarize the findings in a field of study. In the past, reviews were typically narrative—that is, an expert summarized the literature, often without a clear statement of the criteria used for the evaluation. This type of review is considered less rigorous scientifically than the systematic review and of less use in the practice of evidence-based medicine.

A systematic review[2] typically relies on defined criteria:

• Has a specific well-defined question.
• Identifies the methods it used to find the information (e.g., which databases were searched and how they were searched).
• Includes the specific criteria the reviewers used for including and excluding studies.
Many people and organizations conduct systematic reviews. Probably the best known is the Cochrane Collaboration ( The Cochrane Collaboration is a not-for-profit international organization with 14 centres and more than 6000 people in 60 countries working on systematic reviews.[3] The databases held by the Cochrane Library include:
• The Database of Abstracts of Reviews of Effectiveness (systematic reviews that meet quality criteria but are not Cochrane reviews).
• The Cochrane Controlled Trials Register.
• The Cochrane Database of Methodology Reviews (reviews of methodological studies).
• The Cochrane Database of Systematic Reviews.

The Cochrane Database of Systematic Reviews contains reviews that are updated regularly. A Cochrane review always follows defined criteria; it looks at research over time and, in many cases, presents a meta-analysis of the results that provides an indication of where the weight of an entire body of research falls. These reviews are exhaustive in scope and provide an extensive bibliography on the specific topic. The reviews also briefly discuss implications for practice.

Clinical practice guidelines

Clinical practice guidelines are created by many different organizations and can, therefore, vary in quality. A rigorous systematic review of the literature is an important part of creating a clinical guideline. Guidelines are often created by a group of experts and provide explicit recommendations for practice. Two good sources of guidelines are provided by the Canadian Medical Association ( and the National Guideline Clearinghouse (

Aggregated resources

Commercial vendors are now packaging information for the World Wide Web, an example being MDConsult, available through the UBC Library ( and the CMA ( MDConsult aggregates many different resources through one access point or interface. It provides access to online books, an index (MEDLINE), full-text versions of many journals, drug information sources, and patient information. You can search all these resources at once or search a resource individually.

There are obvious advantages to searching many resources at once and to having access to a collection of resources through one vendor. There are also a couple of drawbacks: the search techniques available are fairly simple and searching many resources at once may provide too much information. However, MDConsult is convenient, flexible, and provides good access to a wide array of resources that you might not get in the normal course of buying electronic resources. Another such aggregator is SKOLAR (, which was developed at Stanford University.

Consumer health informatics

Consumers are increasingly searching for health information on the Internet.[4] Many of the resources available to clinicians are also available to consumers. The National Library of Medicine (NLM) in the US, the producer of MEDLINE, also produces MedlinePlus ( MedlinePlus is a resource aimed at the public. It is organized according to disorder categories and provides access to drug information, directories of health organizations, dictionaries, encyclopedias, and tutorials. This site also provides links to the clinical trials database, which informs the public of clinical trials underway in the National Institutes of Health and other US agencies as well as some trials under industry and university sponsorship. At the time of writing, there were 5216 trials listed. This resource and others from reputable organizations offer patients accessible, credible health information.


Why should bioinformatics interest someone in clinical practice? One writer defines bioinformatics as “the computer-assisted data management discipline that helps us gather, analyse, and represent this information.”[5] The sequencing of the human genome has resulted in huge amounts of data and new tools to understand the structure and function of genes and proteins. The results of this research are changing the way we understand diseases in all areas, including etiology, prognosis, diagnosis, and treatment. One example of the implications for practice is research[6] that shows diffuse large B-cell lymphoma has two molecularly distinct forms, and that one of these has a significantly better survival rate. This means a different understanding of prognosis, new diagnostic tests, and better treatments.

As research continues to produce results at an ever-increasing rate, communicating high-quality information to the appropriate people at the point where the information is needed becomes a challenge. Clinicians have access to many new tools and information resources, but there is a need for even more sources that focus on well-evaluated evidence relevant to clinical practice.


The organizations mentioned in this article provide access to many different resources. NLM resources are available to the public, and the CMA, College Medical Library Service, and UBC Library resources are available to their affiliated users.

• National Library of Medicine (—access for the public to MEDLINE and MedlinePlus.
• Canadian Medical Association (—access for members to MDConsult and MEDLINE (Osler) and clinical practice guidelines (Infobase).
• Medical Library Service of the College of Physicians and Surgeons of BC (—access for CPSBC members to the College library and all of its resources, including EBSCO, MEDLINE, and clinical practice guidelines.
• UBC Library (—access for UBC faculty, students, and staff from any networked computer and access for the public from within the UBC Library to MEDLINE, ACP Journal Club, Cochrane Database of Systematic Reviews, and MDConsult.

There are many more resources available through other web sites. Clinicians can benefit from learning about recommended sites and search techniques ( and finding out how to conduct research on the Internet (

Competing interests
None declared.


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4. Fox S, Rainie L. Vital decisions: How Internet users decide what information to trust when they or their loved ones are sick. Pew Internet & American Life Project. (accessed 28 March 2003). 
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6. Alizedah AA, Eisen MB, Davis RE, et al. Distinct types of diffuse large B-cell lymphoma identified by gene expression profiling. Nature 2000; 403:503-511. PubMed Abstract Full Text 

Kathryn Hornby, DMD, MLS, CertMinf

Dr Hornby is a librarian at Woodward Biomedical Library and the Informatics Theme Director in the MD undergraduate program at UBC. She holds a degree in dentistry and a graduate certificate in medical informatics.

Kathryn Hornby, DMD, MLS, CertMinf. The Internet as an evidence-based medicine tool. BCMJ, Vol. 46, No. 6, July, August, 2004, Page(s) 282-284 - Clinical Articles.

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